powershell-5.1-expert

PowerShell 5.1 Expert

Purpose

Provides expertise in Windows PowerShell 5.1 for legacy Windows environments. Specializes in WMI queries, ADSI operations, COM automation, and maintaining scripts compatible with older Windows Server systems.

When to Use

• Scripting for Windows Server 2012/2016/2019
• Working with WMI for system management
• Active Directory operations via ADSI
• COM automation (Office, legacy apps)
• Maintaining backward compatibility
• DSC (Desired State Configuration)
• Windows-specific automation
• Legacy script maintenance

Quick Start

Invoke this skill when:

• Working with Windows PowerShell 5.1 specifically
• Using WMI for system queries
• Automating with ADSI or COM objects
• Maintaining legacy PowerShell scripts
• DSC configuration management

Do NOT invoke when:

• Cross-platform PowerShell → use /powershell-7-expert
• GUI/TUI development → use /powershell-ui-architect
• Security hardening → use /powershell-security-hardening
• Module architecture → use /powershell-module-architect

Decision Framework

PowerShell Version Context?
├── Must run on older Windows
│   └── Use 5.1 with WMI/ADSI
├── Cross-platform needed
│   └── Use PowerShell 7+ instead
├── AD Management
│   ├── Simple → ADSI
│   └── Complex → AD Module
└── System Info
    ├── Legacy → WMI
    └── Modern → CIM (also works in 5.1)

Core Workflows

1. WMI System Query

1. Identify WMI class (Win32_*)
2. Construct WMI query
3. Use Get-WmiObject or Get-CimInstance
4. Filter results appropriately
5. Format output
6. Handle errors for remote systems

2. ADSI Operations

1. Create DirectoryEntry object
2. Navigate LDAP path
3. Query or modify attributes
4. Commit changes if modifying
5. Handle authentication
6. Clean up resources

3. COM Automation

1. Create COM object with New-Object -ComObject
2. Access object model
3. Perform operations
4. Handle COM errors
5. Release COM objects properly
6. Clean up with [System.Runtime.InteropServices.Marshal]

Best Practices

• Use CIM cmdlets over WMI when possible (better remoting)
• Always include error handling for remote operations
• Release COM objects explicitly to prevent memory leaks
• Test on target Windows versions
• Document required PowerShell modules
• Use approved verbs for functions

Anti-Patterns

Anti-Pattern	Problem	Correct Approach
Not releasing COM	Memory leaks	Explicit cleanup
WMI over slow networks	Performance issues	Use CIM with sessions
No error handling	Silent failures	Try/Catch with logging
Hardcoded paths	Portability issues	Use environment variables
Write-Host for output	Can't capture	Write-Output or return