PowerShell for Windows Server Administration: Essential Commands and Scripts

PowerShell is the most powerful administration tool for Windows Server, and since PowerShell 7, it also runs on Linux and macOS. For anyone managing Windows infrastructure — servers, Active Directory, Exchange, or Azure — mastering PowerShell is not optional. It is essential.

This guide covers the most important commands, scripts, and techniques that Windows Server administrators use every day.

Getting Started with PowerShell

# Check PowerShell version
$PSVersionTable.PSVersion

# Get help for any command
Get-Help Get-Process -Full

# Update help files
Update-Help -Force

# Find commands related to a topic
Get-Command *service*
Get-Command -Module ActiveDirectory

PowerShell vs CMD vs Bash

Server Management Essentials

# System information
Get-ComputerInfo | Select-Object CsName, OsName, OsVersion, CsTotalPhysicalMemory

# Check Windows services
Get-Service | Where-Object {$_.Status -eq 'Running'} | Sort-Object DisplayName

# Start/Stop/Restart services
Restart-Service -Name "W3SVC" -Force
Start-Service -Name "MSSQLSERVER"
Stop-Service -Name "Spooler"

# Check disk space on all drives
Get-PSDrive -PSProvider FileSystem | Select-Object Name, 
    @{N='Used(GB)';E={[math]::Round($_.Used/1GB,2)}},
    @{N='Free(GB)';E={[math]::Round($_.Free/1GB,2)}},
    @{N='Total(GB)';E={[math]::Round(($_.Used+$_.Free)/1GB,2)}}

# Check running processes sorted by memory usage
Get-Process | Sort-Object WorkingSet64 -Descending | 
    Select-Object -First 10 Name, Id, 
    @{N='Memory(MB)';E={[math]::Round($_.WorkingSet64/1MB,1)}}

# Event log — last 20 errors
Get-EventLog -LogName System -EntryType Error -Newest 20 | 
    Select-Object TimeGenerated, Source, Message

Active Directory Management

# Import the AD module
Import-Module ActiveDirectory

# Find a user
Get-ADUser -Identity "jsmith" -Properties *

# Search users by name
Get-ADUser -Filter "Name -like '*Johnson*'" | Select-Object Name, SamAccountName, Enabled

# Create a new user
New-ADUser -Name "Jane Doe" -SamAccountName "jdoe" `
    -UserPrincipalName "jdoe@company.com" `
    -GivenName "Jane" -Surname "Doe" `
    -Department "Engineering" `
    -AccountPassword (ConvertTo-SecureString "TempPass123!" -AsPlainText -Force) `
    -Enabled $true -ChangePasswordAtLogon $true

# Disable inactive accounts (no login in 90 days)
$cutoff = (Get-Date).AddDays(-90)
Search-ADAccount -AccountInactive -DateTime $cutoff -UsersOnly | 
    Where-Object {$_.Enabled -eq $true} |
    ForEach-Object {
        Disable-ADAccount $_.SamAccountName
        Write-Host "Disabled: $($_.Name)"
    }

# List all groups a user belongs to
Get-ADPrincipalGroupMembership -Identity "jdoe" | Select-Object Name

# Find locked-out accounts
Search-ADAccount -LockedOut | Select-Object Name, SamAccountName, LastLogonDate

# Unlock an account
Unlock-ADAccount -Identity "jdoe"

# Export all users to CSV
Get-ADUser -Filter * -Properties Department, Title, EmailAddress |
    Select-Object Name, SamAccountName, Department, Title, EmailAddress |
    Export-Csv -Path "C:\Reports\all_users.csv" -NoTypeInformation

Remote Administration

# Enable PowerShell Remoting (run on target server)
Enable-PSRemoting -Force

# Run a command on a remote server
Invoke-Command -ComputerName "Server01" -ScriptBlock {
    Get-Service | Where-Object {$_.Status -eq 'Stopped' -and $_.StartType -eq 'Automatic'}
}

# Interactive remote session
Enter-PSSession -ComputerName "Server01"

# Run on multiple servers simultaneously
$servers = @("Web01", "Web02", "DB01", "App01")
Invoke-Command -ComputerName $servers -ScriptBlock {
    [PSCustomObject]@{
        Server = $env:COMPUTERNAME
        Uptime = (Get-CimInstance Win32_OperatingSystem).LastBootUpTime
        FreeRAM = [math]::Round((Get-CimInstance Win32_OperatingSystem).FreePhysicalMemory/1MB, 2)
    }
} | Format-Table

Automated Reporting Script

# Weekly server health report
function Get-ServerHealthReport {
    param([string[]]$Servers)
    
    $report = foreach ($server in $Servers) {
        try {
            Invoke-Command -ComputerName $server -ScriptBlock {
                $os = Get-CimInstance Win32_OperatingSystem
                $disk = Get-CimInstance Win32_LogicalDisk -Filter "DeviceID='C:'"
                
                [PSCustomObject]@{
                    Server = $env:COMPUTERNAME
                    Status = "Online"
                    Uptime = ((Get-Date) - $os.LastBootUpTime).Days
                    CPULoad = (Get-CimInstance Win32_Processor).LoadPercentage
                    FreeRAM_GB = [math]::Round($os.FreePhysicalMemory/1MB, 1)
                    DiskFree_GB = [math]::Round($disk.FreeSpace/1GB, 1)
                    DiskFree_Pct = [math]::Round($disk.FreeSpace/$disk.Size*100, 0)
                }
            }
        } catch {
            [PSCustomObject]@{
                Server = $server; Status = "OFFLINE"
                Uptime = "N/A"; CPULoad = "N/A"
                FreeRAM_GB = "N/A"; DiskFree_GB = "N/A"; DiskFree_Pct = "N/A"
            }
        }
    }
    
    $report | Format-Table -AutoSize
    $report | Export-Csv "C:\Reports\health_$(Get-Date -f yyyyMMdd).csv" -NoTypeInformation
}

Get-ServerHealthReport -Servers "Web01","Web02","DB01"

Practical Automation Scripts

# Clean up old files (IIS logs older than 30 days)
Get-ChildItem "C:\inetpub\logs\LogFiles" -Recurse -File |
    Where-Object {$_.LastWriteTime -lt (Get-Date).AddDays(-30)} |
    Remove-Item -Force -Verbose

# Monitor a service and restart if stopped
$service = "W3SVC"
while ($true) {
    $status = (Get-Service $service).Status
    if ($status -ne 'Running') {
        Write-Host "$(Get-Date): $service is $status — restarting..."
        Start-Service $service
        # Send email alert here
    }
    Start-Sleep -Seconds 60
}

# Bulk create DNS records
$records = Import-Csv "dns_records.csv"  # Columns: Name, IP
foreach ($record in $records) {
    Add-DnsServerResourceRecordA -ZoneName "company.com" `
        -Name $record.Name -IPv4Address $record.IP
    Write-Host "Created: $($record.Name).company.com -> $($record.IP)"
}

Conclusion

PowerShell transforms Windows Server administration from a manual, GUI-heavy process into an efficient, scriptable, and repeatable workflow. The commands in this guide represent the core toolkit every Windows administrator needs. Start with the basics, build scripts for your most repetitive tasks, and gradually automate more of your infrastructure management.

Whether you manage 5 servers or 500, PowerShell is the key to doing it efficiently and reliably.