
In this article, we shall discuss “KB5034439 Windows Update Error: Resize WinRE Partition”. Microsoft has revised the update process for Windows Recovery Environment (WinRE) on PCs receiving updates. From Windows Update (WU) and Windows Server Update Services (WSUS). Please see What are System Partition and Boot Partition in Windows, How to create a BitLocker System Partition [Part 2], and How to extend System Drive Partition on Windows.
Note: Starting with the Windows 11, version 22H2 cumulative update on June 27, 2023, WinRE will be updated alongside the monthly cumulative update.
However, some PCs may encounter update failures as shown in the image below. This is due to insufficient space in the recovery partition. To address this, manual resizing of the recovery partition is necessary if the system encounters an ErrorPhase of 2. This procedure assumes that the recovery partition is located after the OS partition.

How can I obtain this update?
This update cannot be gotten via Microsoft Update Catalog, or Windows Server Update Services (WSUS) and Microsoft Endpoint Configuration Manager. But via Windows Update only.

Note: If your running PC lacks a WinRE recovery partition, you don’t require this update.
Please see “Fix “Getting Windows Ready” Don’t turn off your computer stuck on Windows“, and how to fix “Failure 5456: Unable to determine destination disk, partition, and/or drive, see BDD Log“.
Is WinRE enabled?
To confirm if WinRE is enabled, run the following command in an elevated command prompt below. If WinRE is enabled, you will see Windows RE status in the output with a value of Enabled.
reagentc /info

Here is how to fix “Faulting Application Name: mmc.exe: Unable to launch ADUC“, and “Fix AirDrop issue “No People found and there is no one nearby to share with” on Mac“.
Extend the WinRE Partition
The Windows Server must have 250MB of free space in the recovery partition to apply this update successfully.
To avoid this error or recover from this failure, please resize your partition to be able to install the WinRE update.
When this is done, try installing this update. Remember to add the .ps1

Note: This is a script from Microsoft. Therefore, the credit goes to them
Param ([Parameter(Mandatory=$false,HelpMessage="Skip confirmation")][bool]$SkipConfirmation=$false,[Parameter(Mandatory=$true,HelpMessage="Path to backup old WinRE partition content to")][string]$BackupFolder)# ------------------------------------# Helper functions# ------------------------------------# Log messagefunction LogMessage([string]$message){ $message = "$message" Write-Host $message}# Extract numbers from stringfunction ExtractNumbers([string]$str){ $cleanString = $str -replace "[^0-9]" return [long]$cleanString}# Display partition info using fsutil# Return an array, the first value is total size and the second value is free spacefunction DisplayPartitionInfo([string[]]$partitionPath){ $volume = Get-WmiObject -Class Win32_Volume | Where-Object { $partitionPath -contains $_.DeviceID } LogMessage(" Partition capacity: " + $volume.Capacity) LogMessage(" Partition free space: " + $volume.FreeSpace) return $volume.Capacity, $volume.FreeSpace} # Display WinRE statusfunction DisplayWinREStatus(){ # Get WinRE partition info $WinREInfo = Reagentc /info foreach ($line in $WinREInfo) { $params = $line.Split(':') if ($params.Count -lt 2) { continue } if (($params[1].Trim() -ieq "Enabled") -Or (($params[1].Trim() -ieq "Disabled"))) { $Status = $params[1].Trim() -ieq "Enabled" LogMessage($line.Trim()) } if ($params[1].Trim() -like "\\?\GLOBALROOT*") { $Location = $params[1].Trim() LogMessage($line.Trim()) } } return $Status, $Location}# ------------------------------------# Main execution# ------------------------------------# Clear the error$Error.Clear()# ------------------------------------# Examining the system to collect required info # for the execution# Need to check WinRE status, collect OS and WinRE# partition info# ------------------------------------LogMessage("Start time: $([DateTime]::Now)")LogMessage("Examining the system...")$NeedShrink = $true$NeedCreateNew = $false$NeedBackup = $false# Get WinRE partition info$InitialWinREStatus = DisplayWinREStatus$WinREStatus = $InitialWinREStatus[0]$WinRELocation = $InitialWinREStatus[1]if (!$WinREStatus){ LogMessage("Error: WinRE Disabled") exit 1}# Get System directory and ReAgent xml file$system32Path = [System.Environment]::SystemDirectoryLogMessage("System directory: " + $system32Path)$ReAgentXmlPath = Join-Path -Path $system32Path -ChildPath "\Recovery\ReAgent.xml"LogMessage("ReAgent xml: " + $ReAgentXmlPath)if (!(Test-Path $ReAgentXmlPath)){ LogMessage("Error: ReAgent.xml cannot be found") exit 1}# Get OS partitionLogMessage("")LogMessage("Collecting OS and WinRE partition info...")$OSDrive = $system32Path.Substring(0,1)$OSPartition = Get-Partition -DriveLetter $OSDrive# Get WinRE partition$WinRELocationItems = $WinRELocation.Split('\\')foreach ($item in $WinRELocationItems){ if ($item -like "harddisk*") { $OSDiskIndex = ExtractNumbers($item) } if ($item -like "partition*") { $WinREPartitionIndex = ExtractNumbers($item) }}LogMessage("OS Disk: " + $OSDiskIndex)LogMessage("OS Partition: " + $OSPartition.PartitionNumber)LogMessage("WinRE Partition: " + $WinREPartitionIndex)$WinREPartition = Get-Partition -DiskNumber $OSDiskIndex -PartitionNumber $WinREPartitionIndex$diskInfo = Get-Disk -number $OSDiskIndex$diskType = $diskInfo.PartitionStyleLogMessage("Disk PartitionStyle: " + $diskType)# Display WinRE partition size infoLogMessage("WinRE partition size info")$WinREPartitionSizeInfo = DisplayPartitionInfo($WinREPartition.AccessPaths)LogMessage("WinRE Partition Offset: " + $WinREPartition.Offset)LogMessage("WinRE Partition Type: " + $WinREPartition.Type)LogMessage("OS partition size: " + $OSPartition.Size)LogMessage("OS partition Offset: " + $OSPartition.Offset)$OSPartitionEnds = $OSPartition.Offset + $OSPartition.SizeLogMessage("OS partition ends at: " + $OSPartitionEnds)LogMessage("WinRE partition starts at: " + $WinREPartition.Offset)$WinREIsOnSystemPartition = $falseif ($diskType -ieq "MBR"){ if ($WinREPartition.IsActive) { LogMessage("WinRE is on System partition") $WinREIsOnSystemPartition = $true }}if ($diskType -ieq "GPT"){ if ($WinREPartition.Type -ieq "System") { LogMessage("WinRE is on System partition") $WinREIsOnSystemPartition = $true }}# Checking the BackupFolder parameterif ($PSBoundParameters.ContainsKey('BackupFolder')){ LogMessage("") LogMessage("Backup Directory: [" + $BackupFolder + "]") $Needbackup = $true if ($WinREIsOnSystemPartition) { $Needbackup = $false LogMessage("WinRE is on System partition which will be preserved. No need to backup content") } else { if (Test-path $BackupFolder) { $items = Get-ChildItem -Path $BackupFolder if ($items) { LogMessage("Error: Existing backup directory is not empty") exit 1 } } else { LogMessage("Creating backup directory...") try { $item = New-Item -Path $BackupFolder -ItemType Directory -ErrorAction Stop if ($item) { LogMessage("Backup directory created") } else { LogMessage("Error: Failed to create backup directory [" + $BackupFolder + "]") exit 1 } } catch { LogMessage("Error: An error occurred: $_") exit 1 } } }}# ------------------------------------# Verify whether we meet requirements of execution# - WinRE cannot be on OS partition for the extension# - WinRE partition must be the next partition after OS partition# - If WinRE partition already have >=250MB free space, no need to do repartition# - If there is enough unallocated space to grow the WinRE partition size, skip shrinking OS# # However, if the WinRE partition is before the OS partition, there is no chance to extend it# As a result, it's better to create a new WinRE partition after the OS partition# ------------------------------------# Perform a few checksLogMessage("")LogMessage("Verifying if the WinRE partition needs to be extended or not...")if (!(($diskType -ieq "MBR") -Or ($diskType -ieq "GPT"))){ LogMessage("Error: Got an unexpected disk partition style: " +$diskType) exit 1}# WinRE partition must be after OS partition for the repartitionif ($WinREPartitionIndex -eq $OSPartition.PartitionNumber){ LogMessage("WinRE and OS are on the same partition, should not perform extension") exit 0}$supportedSize = Get-PartitionSupportedSize -DriveLetter $OSDrive# if there is enough free space, skip extensionif ($WinREPartitionSizeInfo[1] -ge 250MB){ LogMessage("More than 250 MB of free space was detected in the WinRE partition, there is no need to extend the partition") exit 0}if ($WinREPartition.Offset -lt $OSPartitionEnds){ LogMessage("WinRE partition is not after OS partition, cannot perform extension") LogMessage("Need to create a new WinRE partition after OS partition") $NeedCreateNew = $true $NeedShrink = $true # Calculate the size of repartition # Will create a new WinRE partition with current WinRE partition size + 250 MB # The OS partition size will be shrunk by the new WinRE partition size $targetWinREPartitionSize = $WinREPartitionSizeInfo[0] + 250MB $shrinkSize = [Math]::Ceiling($targetWinREPartitionSize / 1MB) * 1MB $targetOSPartitionSize = $OSPartition.Size - $shrinkSize if ($targetOSPartitionSize -lt $supportedSize.SizeMin) { LogMessage("Error: The target OS partition size after shrinking is smaller than the supported minimum size, cannot perform the repartition") exit 1 }}else{ if ($WinREIsOnSystemPartition) { LogMessage("WinRE parititon is after the OS partition and it's also System partition") LogMessage("Error: Got unexpected disk layout, cannot proceed") exit 1 } if (!($WinREPartitionIndex -eq ($OSPartition.PartitionNumber + 1))) { LogMessage("Error: WinRE partition is not right after the OS partition, cannot extend WinRE partition") exit 1 } # Calculate the size of repartition # Will shrink OS partitition by 250 MB $shrinkSize = 250MB $targetOSPartitionSize = $OSPartition.Size - $shrinkSize $targetWinREPartitionSize = $WinREPartitionSizeInfo[0] + 250MB $UnallocatedSpace = $WinREPartition.Offset - $OSPartitionEnds; # If there is unallocated space, consider using it if ($UnallocatedSpace -ge 250MB) { $UnallocatedSpace = $WinREPartition.Offset - $OSPartitionEnds; LogMessage("Found unallocated space between OS and WinRE partition: " + $UnallocatedSpace) LogMessage("There is already enough space to extend WinRE partition without shrinking the OS partition") $NeedShrink = $false $targetOSPartitionSize = 0 } else { $shrinkSize = [Math]::Ceiling((250MB - $UnallocatedSpace)/ 1MB) * 1MB if ($shrinkSize > 250MB) { $shrinkSize = 250MB } $targetOSPartitionSize = $OSPartition.Size - $shrinkSize if ($targetOSPartitionSize -lt $supportedSize.SizeMin) { LogMessage("Error: The target OS partition size after shrinking is smaller than the supported minimum size, cannot perform the repartition") exit 1 } }}# ------------------------------------# Report execution plan and ask for user confirmation to continue# ------------------------------------# Report the changes planned to be executed, waiting for user confirmationLogMessage("")LogMessage("Summary of proposed changes")if ($NeedCreateNew){ LogMessage("Note: WinRE partition is before OS partition, need to create a new WinRE partition after OS partition") LogMessage("Will shrink OS partition by " + $shrinkSize) LogMessage(" Current OS partition size: " + $OSPartition.Size) LogMessage(" Target OS partition size after shrinking: " + $targetOSPartitionSize) LogMessage("New WinRE partition will be created with size: ", $targetWinREPartitionSize) if ($WinREIsOnSystemPartition) { LogMessage("Existing WinRE partition is also system partition, it will be preserved") } else { LogMessage("Existing WinRE partition will be deleted") LogMessage(" WinRE partition: Disk [" + $OSDiskIndex + "] Partition [" + $WinREPartitionIndex + "]") LogMessage(" Current WinRE partition size: " + $WinREPartitionSizeInfo[0]) }}else{ if ($NeedShrink) { LogMessage("Will shrink OS partition by " + $shrinkSize) LogMessage(" Current OS partition size: " + $OSPartition.Size) LogMessage(" Target OS partition size after shrinking: " + $targetOSPartitionSize) if ($UnallocatedSpace -ge 0) { LogMessage("Unallocated space between OS and WinRE partition that will be used towards the new WinRE partition: " + $UnallocatedSpace) } } else { LogMessage("Will use 250MB from unallocated space between OS and WinRE partition") } LogMessage("Will extend WinRE partition size by 250MB") LogMessage(" WinRE partition: Disk [" + $OSDiskIndex + "] Partition [" + $WinREPartitionIndex + "]") LogMessage(" Current WinRE partition size: " + $WinREPartitionSizeInfo[0]) LogMessage(" New WinRE partition size: " + $targetWinREPartitionSize) LogMessage("WinRE will be temporarily disabled before extending the WinRE partition and enabled automatically in the end") if ($UnallocatedSpace -ge 100MB) { LogMessage("Warning: More than 100MB of unallocated space was detected between the OS and WinRE partitions") LogMessage("Would you like to proceed by using the unallocated space between the OS and the WinRE partitions?") }}if ($Needbackup){ LogMessage("") LogMessage("The contents of the old WinRE partition will be backed up to [" + $BackupFolder + "]")}LogMessage("")LogMessage("Please reboot the device before running this script to ensure any pending partition actions are finalized")LogMessage("")if ($SkipConfirmation){ LogMessage("User chose to skip confirmation") LogMessage("Proceeding with changes...")}else{ $userInput = Read-Host -Prompt "Would you like to proceed? Y for Yes and N for No" if ($userInput -ieq "Y") { LogMessage("Proceeding with changes...") } elseif ($userInput -ieq "N") { LogMessage("Canceling based on user request, no changes were made to the system") exit 0 } else { LogMessage("Error: Unexpected user input: [" + $userInput + "]") exit 0 }}LogMessage("")LogMessage("Note: To prevent unexpected results, please do not interrupt the execution or restart your system")# ------------------------------------# Do the actual execution# The main flow is:# 1. Check whether ReAgent.xml has stage location and clear it for repartiion# 2. Disable WinRE as WinRE partition will be deleted# 3. Perform the repartition to create a larger WinRE partition# 4. Re-enable WinRE# ------------------------------------LogMessage("")# Load ReAgent.xml to clear Stage locationLogMessage("Loading [" + $ReAgentXmlPath + "] ...")$xml = [xml](Get-Content -Path $ReAgentXmlPath)$node = $xml.WindowsRE.ImageLocationif (($node.path -eq "") -And ($node.guid -eq "{00000000-0000-0000-0000-000000000000}") -And ($node.offset -eq "0") -And ($node.id -eq "0")){ LogMessage("Stage location info is empty")}else{ LogMessage("Clearing stage location info...") $node.path = "" $node.offset = "0" $node.guid= "{00000000-0000-0000-0000-000000000000}" $node.id="0" # Save the change LogMessage("Saving changes to [" + $ReAgentXmlPath + "]...") $xml.Save($ReAgentXmlPath)}# Disable WinRELogMessage("Disabling WinRE...")reagentc /disableif (!($LASTEXITCODE -eq 0)){ LogMessage("Warning: encountered an error when disabling WinRE: " + $LASTEXITCODE) exit $LASTEXITCODE}# Verify WinRE is under C:\Windows\System32\Recovery\WinRE.wim$disableWinREPath = Join-Path -Path $system32Path -ChildPath "\Recovery\WinRE.wim"LogMessage("Verifying that WinRE wim exists in downlevel at default location")if (!(Test-Path $disableWinREPath)){ LogMessage("Error: Cannot find " + $disableWinREPath) # Re-enable WinRE LogMessage("Re-enabling WinRE on error...") reagentc /enable if (!($LASTEXITCODE -eq 0)) { LogMessage("Warning: encountered an error when enabling WinRE: " + $LASTEXITCODE) } exit 1}# ------------------------------------# Perform the repartition# 1. Resize the OS partition# 2. Delete the WinRE partition# 3. Create a new WinRE partition# ------------------------------------LogMessage("Performing repartition to extend the WinRE partition ...")# 1. Resize the OS partitionif ($NeedShrink){ LogMessage("Shrinking the OS partition to create a larger WinRE partition") LogMessage("Resizing the OS partition to: [" + $targetOSPartitionSize + "]...") Resize-Partition -DriveLetter $OSDrive -Size $targetOSPartitionSize if ($Error.Count -gt 0) { LogMessage("Error: Resize-Partition encountered errors: " + $Error[0].Exception.Message) # Re-enable WinRE LogMessage("Re-enabling WinRE on error...") reagentc /enable if (!($LASTEXITCODE -eq 0)) { LogMessage("Warning: encountered an error when enabling WinRE: " + $LASTEXITCODE) } exit 1 } $OSPartitionAfterShrink = Get-Partition -DriveLetter $OSDrive LogMessage("Target partition size: " + $targetOSPartitionSize) LogMessage("Size of OS partition after shrinking: " + $OSPartitionAfterShrink.Size)}# 2. Delete the WinRE partitionLogMessage("")if ($WinREIsOnSystemPartition){ LogMessage("Existing WinRE partition is System partition, skipping deletion")}else{ # If requested by user, backup rest of the content on WinRE partition to backup directory if ($Needbackup) { $sourcePath = $WinREPartition.AccessPaths[0] LogMessage("Copying content on WinRE partition from [" + $sourcePath + "] to [" + $BackupFolder + "]...") # Copy-Item may have access issue with certain system folders, enumerate the children items and exlcude them $items = Get-ChildItem -LiteralPath $sourcePath -Force foreach ($item in $items) { if ($item.Name -ieq "System Volume Information") { continue } $sourceItemPath = Join-Path -Path $sourcePath -ChildPath $item.Name $destItemPath = Join-Path -Path $BackupFolder -ChildPath $item.Name try { LogMessage("Copying [" + $sourceItemPath + "] to [" + $destItemPath + "]...") Copy-Item -LiteralPath $sourceItemPath -Destination $destItemPath -Recurse -Force } catch { LogMessage("Error: An error occurred during copy: $_") exit 1 } } LogMessage("Backup completed") LogMessage("") } LogMessage("Deleting WinRE partition: Disk [" + $OSDiskIndex + "] Partition [" + $WinREPartitionIndex + "]...") Remove-Partition -DiskNumber $OSDiskIndex -PartitionNumber $WinREPartitionIndex -Confirm:$false if ($Error.Count -gt 0) { LogMessage("Error: Remove-Partition encountered errors: " + $Error[0].Exception.Message) exit 1 }}# A short sleep for the partition changeSleep 5# 3. Create a new WinRE partitionLogMessage("")LogMessage("Creating new WinRE partition...")LogMessage("Target size: " + $targetWinREPartitionSize)if ($diskType -ieq "GPT"){ $partition = New-Partition -DiskNumber $OSDiskIndex -Size $targetWinREPartitionSize -GptType "{de94bba4-06d1-4d40-a16a-bfd50179d6ac}" $newPartitionIndex = $partition.PartitionNumber # A short sleep to make sure the partition is ready for formatting Sleep 2 LogMessage("Formating the partition...") $result = Format-Volume -Partition $partition -FileSystem NTFS -Confirm:$false if ($Error.Count -gt 0) { LogMessage("Error: Format-Volume encountered errors: " + $Error[0].Exception.Message) exit 1 }}else{ #$partition = New-Partition -DiskNumber $OSDiskIndex -Size $targetWinREPartitionSize -MbrType 0x27 $targetWinREPartitionSizeInMb = [int]($targetWinREPartitionSize/1MB) $diskpartScript = @"select disk $OSDiskIndexcreate partition primary size=$targetWinREPartitionSizeInMb id=27format quick fs=ntfs label="Recovery"set id=27"@ $TempPath = $env:Temp $diskpartSciptFile = Join-Path -Path $TempPath -ChildPath "\ExtendWinRE_MBR_PowershellScript.txt" LogMessage("Creating temporary diskpart script to create Recovery partition on MBR disk...") LogMessage("Temporary diskpart script file: " + $diskpartSciptFile) $diskpartScript | Out-File -FilePath $diskpartSciptFile -Encoding ascii LogMessage("Executing diskpart script...") try { $diskpartOutput = diskpart /s $diskpartSciptFile if ($diskpartOutput -match "DiskPart successfully") { LogMessage("Diskpart script executed successfully") } else { LogMessage("Error executing diskpart script:" + $diskpartOutput) exit 1 } LogMessage("Deleting temporary diskpart script file...") Remove-Item $diskpartSciptFile } catch { LogMessage("Error executing diskpart script: $_") exit 1 } $vol = Get-Volume -FileSystemLabel "Recovery" $newPartitionIndex = (Get-Partition | Where-Object { $_.AccessPaths -contains $vol.Path } ).PartitionNumber}if ($Error.Count -gt 0) { LogMessage("Error: New-Partition encountered errors: " + $Error[0].Exception.Message) exit 1}LogMessage("New Partition index: " + $newPartitionIndex)# Re-enable WinRELogMessage("Re-enabling WinRE...")reagentc /enableif (!($LASTEXITCODE -eq 0)){ LogMessage("Warning: encountered an error when enabling WinRE: " + $LASTEXITCODE) exit $LASTEXITCODE}# In the end, Display WinRE status to verify WinRE is enabled correctlyLogMessage("")LogMessage("WinRE Information:")$FinalWinREStatus = DisplayWinREStatus$WinREStatus = $FinalWinREStatus[0]$WinRELocation = $FinalWinREStatus[1]if (!$WinREStatus){ LogMessage("Warning: WinRE Disabled")}$WinRELocationItems = $WinRELocation.Split('\\')foreach ($item in $WinRELocationItems){ if ($item -like "partition*") { $WinREPartitionIndex = ExtractNumbers($item) }}LogMessage("WinRE Partition Index: " + $WinREPartitionIndex)$WinREPartition = Get-Partition -DiskNumber $OSDiskIndex -PartitionNumber $WinREPartitionIndex$WinREPartitionSizeInfoAfter = DisplayPartitionInfo($WinREPartition.AccessPaths)LogMessage("")LogMessage("OS Information:")$OSPartition = Get-Partition -DriveLetter $OSDriveLogMessage("OS partition size: " + $OSPartition.Size)LogMessage("OS partition Offset: " + $OSPartition.Offset)if (!($WinREPartitionIndex -eq $newPartitionIndex)){ LogMessage("Warning: WinRE is installed to partition [" + $WinREPartitionIndex +"], but the newly created Recovery partition is [" + $newPartitionIndex + "]")}LogMessage("End time: $([DateTime]::Now)")if ($NeedBackup){ LogMessage("") LogMessage("The contents of the old WinRE partition has been backed up to [" + $BackupFolder + "]")}LogMessage("")LogMessage("Successfully completed the operation")
Run the WinRE Script from Microsoft
Launch PowerShell as an Administrator. You can also select a different user that has the administrative right on the Server.

Note: Before running the script, ensure your machine is rebooted to finalize any pending partition operations. This step is crucial for the safe extension of the WinRE partition. Once rebooted.
If your device lacks sufficient free space, you can utilize the sample script provided above to extend the recovery partition by 250MB. If deploying this solution at scale, you can bypass script prompting by utilizing the parameters.
-SkipConfirmation $true -BackupFolder


Please run the Windows Update once again. It should succeed.

Manually resize your partition
You can manually resize your partition to install the WinRE update. Please use this link to shrink, delete and manually create a new WinRE Recovery Partition
I hope you found this article on “KB5034439 Windows Update Error: Resize WinRE Partition’ very useful. Please feel free to leave a comment below.