How to Perform an In-Place Upgrade to Windows Server 2025

Before starting the upgrade, you need to document your current system configuration and ensure compatibility. This step prevents surprises during the upgrade process.

Open PowerShell as Administrator and run the following command to check your current Windows version:

Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, WindowsBuildLabEx, WindowsEditionId

Next, document all installed roles and features that need to be preserved:

Get-WindowsFeature | Where-Object {$_.InstallState -eq 'Installed'} | Format-Table DisplayName, Name -AutoSize

Export this list to a file for reference:

Get-WindowsFeature | Where-Object {$_.InstallState -eq 'Installed'} | Export-Csv -Path C:\temp\installed-features.csv -NoTypeInformation

Critical services like backup software can interfere with the upgrade process. Stop these services now to prevent corruption or upgrade failures.

Stop common services that may cause issues:

# Stop Veeam services if installed
Get-Service | Where-Object {$_.Name -like "*Veeam*"} | Stop-Service -Force

# Stop antivirus services (example for Windows Defender)
Stop-Service -Name "WinDefend" -Force

# Stop any custom backup or monitoring agents
# Replace with your specific service names
Stop-Service -Name "YourBackupService" -Force

Verify services are stopped:

Get-Service | Where-Object {$_.Name -like "*Veeam*" -or $_.Name -eq "WinDefend"} | Select-Object Name, Status

Create a system state backup using Windows Server Backup:

# Install Windows Server Backup if not already installed
Install-WindowsFeature -Name Windows-Server-Backup

# Create system state backup (adjust path as needed)
wbadmin start systemstatebackup -backupTarget:E:\ -quiet

Mount the Windows Server 2025 ISO file and verify you have the correct edition that matches your current installation. Edition mismatches will prevent the in-place upgrade option from appearing.

Mount the ISO file (replace path with your actual ISO location):

# Mount ISO using PowerShell
$ISOPath = "C:\ISOs\WindowsServer2025.iso"
Mount-DiskImage -ImagePath $ISOPath

# Get the drive letter of the mounted ISO
$DriveLetter = (Get-DiskImage -ImagePath $ISOPath | Get-Volume).DriveLetter
Write-Host "ISO mounted to drive: $DriveLetter"

# Navigate to the mounted drive
Set-Location "${DriveLetter}:"
dir

Verify the setup files are present and check the available editions:

# List available Windows editions in the ISO
dism /Get-WimInfo /WimFile:sources\install.wim

The output will show index numbers for different editions:

• Index 1: Windows Server 2025 Standard (Server Core)
• Index 2: Windows Server 2025 Standard (Desktop Experience)
• Index 3: Windows Server 2025 Datacenter (Server Core)
• Index 4: Windows Server 2025 Datacenter (Desktop Experience)

Before starting the actual upgrade, run the setup compatibility check to identify potential issues. This step helps you address problems before they cause upgrade failures.

From the mounted ISO drive, run the setup with compatibility check only:

setup.exe /Compat ScanOnly

This will launch the Windows Setup wizard in compatibility check mode. Follow these steps:

1. Click "Next" when the setup starts
2. Enter your Windows Server 2025 product key when prompted
3. Accept the license terms
4. The setup will scan for compatibility issues

Review any compatibility warnings or errors. Common issues include:

• Incompatible applications that need to be uninstalled
• Hardware drivers that may not work with Server 2025
• Features or roles that aren't supported in the new version

Address any critical issues before proceeding. For non-critical warnings, you can choose to ignore them during the actual upgrade.

Now perform the actual upgrade using the graphical interface. This method provides more control and visibility into the upgrade process.

From the mounted ISO drive, run setup as Administrator:

setup.exe

Follow these steps in the Windows Setup wizard:

1. Get important updates: Choose "Download updates, drivers and optional features" for the latest compatibility updates
2. Product key: Enter your Windows Server 2025 product key
3. License terms: Accept the license agreement
4. Choose what to keep: Select "Keep personal files and apps" - this is the key option for in-place upgrade
5. Ready to install: Review the summary and click "Install"

The upgrade process will take 1-3 hours depending on your system. The server will restart multiple times automatically. You'll see progress screens showing:

• Copying Windows files
• Installing features and drivers
• Configuring settings
• Installing updates

Do not interrupt this process or power off the server during upgrades.

For environments where you need to automate the upgrade or prefer command-line control, use this method instead of the GUI approach.

From an elevated PowerShell prompt on the mounted ISO drive, run:

# For Windows Server 2025 Datacenter Desktop Experience
.\setup.exe /auto upgrade /quiet /imageindex 4 /DynamicUpdate Disable /Compat IgnoreWarning /eula accept

# For Windows Server 2025 Standard Desktop Experience
.\setup.exe /auto upgrade /quiet /imageindex 2 /DynamicUpdate Disable /Compat IgnoreWarning /eula accept

Command parameters explained:

• /auto upgrade - Performs in-place upgrade keeping all settings and apps
• /quiet - Runs without user prompts
• /imageindex 4 - Specifies Datacenter Desktop Experience (adjust as needed)
• /DynamicUpdate Disable - Skips downloading updates during setup
• /Compat IgnoreWarning - Bypasses non-critical compatibility warnings
• /eula accept - Automatically accepts license terms

Monitor the upgrade progress by checking the setup log:

# Monitor setup progress (run from another PowerShell window)
Get-Content C:\Windows\Panther\setupact.log -Wait -Tail 10

After the upgrade completes and you can log in, verify that Windows Server 2025 is running correctly and all your roles and features are intact.

Check the Windows version and build:

Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, WindowsBuildLabEx, WindowsEditionId

# Alternative method
winver

Verify all previously installed roles and features are still present:

# Compare with your pre-upgrade export
Get-WindowsFeature | Where-Object {$_.InstallState -eq 'Installed'} | Format-Table DisplayName, Name -AutoSize

# Check specific critical roles (adjust for your environment)
Get-WindowsFeature | Where-Object {$_.Name -like "*IIS*" -or $_.Name -like "*AD-Domain*" -or $_.Name -like "*DHCP*"} | Select-Object DisplayName, InstallState

Verify system services are running:

# Check critical Windows services
Get-Service | Where-Object {$_.Name -in @("Spooler", "BITS", "Themes", "AudioSrv", "Dhcp", "DNS")} | Select-Object Name, Status

# Check domain controller services if applicable
Get-Service | Where-Object {$_.Name -like "*NTDS*" -or $_.Name -like "*KDC*"} | Select-Object Name, Status

Test network connectivity and domain membership:

# Test network connectivity
Test-NetConnection -ComputerName "8.8.8.8" -Port 53

# Verify domain membership (if domain-joined)
Get-ComputerInfo | Select-Object Domain, PartOfDomain

# Test domain controller connectivity (if applicable)
nltest /dclist:yourdomain.com

After the upgrade, you need to reactivate Windows Server 2025 and install the latest security updates to ensure your system is fully protected.

Check current activation status:

# Check activation status
slmgr /xpr

# Get detailed licensing information
slmgr /dlv

If activation is needed, activate using your product key:

# Install product key (replace with your actual key)
slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

# Activate online
slmgr /ato

# For KMS activation (if using KMS server)
slmgr /skms your-kms-server.domain.com
slmgr /ato

Install Windows Updates:

# Install PSWindowsUpdate module if not present
Install-Module PSWindowsUpdate -Force

# Check for available updates
Get-WUList

# Install all available updates
Install-WindowsUpdate -AcceptAll -AutoReboot

# Alternative: Use Windows Update GUI
# Go to Settings > Update & Security > Windows Update

Verify activation and update status:

# Confirm activation
slmgr /xpr

# Check update history
Get-WUHistory | Select-Object Title, Date, Result | Sort-Object Date -Descending | Select-Object -First 10

Restart the services you stopped before the upgrade and validate that all your applications and server roles are functioning correctly.

Restart previously stopped services:

# Restart Veeam services if they were stopped
Get-Service | Where-Object {$_.Name -like "*Veeam*"} | Start-Service

# Restart Windows Defender
Start-Service -Name "WinDefend"

# Restart any custom services you stopped
Start-Service -Name "YourBackupService"

# Verify services are running
Get-Service | Where-Object {$_.Name -like "*Veeam*" -or $_.Name -eq "WinDefend"} | Select-Object Name, Status

Test critical server roles and applications:

# Test IIS if installed
if (Get-WindowsFeature -Name "IIS-WebServer" | Where-Object {$_.InstallState -eq "Installed"}) {
    Invoke-WebRequest -Uri "http://localhost" -UseBasicParsing
}

# Test DHCP if installed
if (Get-WindowsFeature -Name "DHCP" | Where-Object {$_.InstallState -eq "Installed"}) {
    Get-DhcpServerv4Scope
}

# Test DNS if installed
if (Get-WindowsFeature -Name "DNS" | Where-Object {$_.InstallState -eq "Installed"}) {
    Get-DnsServerZone
}

Validate Active Directory services if this is a domain controller:

# Check AD replication status
repadmin /replsummary

# Verify SYSVOL replication
dfsrdiag pollad

# Test domain controller functionality
dcdiag /v

Test application connectivity and functionality:

# Test SQL Server connectivity if installed
if (Get-Service -Name "MSSQLSERVER" -ErrorAction SilentlyContinue) {
    sqlcmd -S localhost -Q "SELECT @@VERSION"
}

# Test file shares
Get-SmbShare | Select-Object Name, Path, Description

Complete a comprehensive system health check and document the upgrade for future reference and compliance purposes.

Run a complete system health assessment:

# Check system file integrity
sfc /scannow

# Run DISM health check
Dism /Online /Cleanup-Image /CheckHealth
Dism /Online /Cleanup-Image /ScanHealth

# Check disk health
Get-PhysicalDisk | Get-StorageReliabilityCounter | Select-Object DeviceId, Temperature, ReadErrorsTotal, WriteErrorsTotal

# Verify event logs for critical errors
Get-EventLog -LogName System -EntryType Error -Newest 50 | Select-Object TimeGenerated, Source, EventID, Message

Document the upgrade completion:

# Create upgrade completion report
$UpgradeReport = @{
    "UpgradeDate" = Get-Date
    "PreviousVersion" = "Windows Server 2019/2022"  # Update based on your starting version
    "CurrentVersion" = (Get-ComputerInfo).WindowsProductName
    "BuildNumber" = (Get-ComputerInfo).WindowsBuildLabEx
    "ActivationStatus" = (slmgr /xpr | Out-String)
    "InstalledFeatures" = (Get-WindowsFeature | Where-Object {$_.InstallState -eq 'Installed'}).Count
}

$UpgradeReport | ConvertTo-Json | Out-File -FilePath "C:\temp\Server2025-Upgrade-Report.json"

# Export current system configuration
Get-ComputerInfo | Export-Clixml -Path "C:\temp\Post-Upgrade-SystemInfo.xml"
Get-WindowsFeature | Where-Object {$_.InstallState -eq 'Installed'} | Export-Csv -Path "C:\temp\Post-Upgrade-Features.csv" -NoTypeInformation

Clean up upgrade files and temporary data:

# Clean up Windows Update files
Dism /Online /Cleanup-Image /StartComponentCleanup /ResetBase

# Clean temporary files
Get-ChildItem -Path $env:TEMP -Recurse | Remove-Item -Force -Recurse -ErrorAction SilentlyContinue

# Dismount the ISO if still mounted
$ISOPath = "C:\ISOs\WindowsServer2025.iso"  # Adjust path
Dismount-DiskImage -ImagePath $ISOPath

Schedule regular maintenance tasks:

# Create scheduled task for monthly Windows Updates
$Action = New-ScheduledTaskAction -Execute "PowerShell.exe" -Argument "-Command Install-WindowsUpdate -AcceptAll -AutoReboot"
$Trigger = New-ScheduledTaskTrigger -Weekly -DaysOfWeek Sunday -At 3AM
$Settings = New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -DontStopIfGoingOnBatteries
Register-ScheduledTask -TaskName "Monthly Windows Updates" -Action $Action -Trigger $Trigger -Settings $Settings -User "SYSTEM"