Get-ItemProperty and Set-ItemProperty are most useful when manipulating registry values.

The following method may be used to get values from the registry:

Get-ItemProperty -Path HKCU:Environment 
Get-ItemProperty -Path HKCU:Environment -Name Path 
Get-ItemProperty -Path HKCU:Environment -Name Path, Temp 

Individual values may be written back to the registry under an existing key:

Set-ItemProperty -Path HKCU:Environment -Name NewValue -Value 'New' 

A value may be subsequently removed:

Remove-ItemProperty -Path HKCU:Environment -Name NewValue 

The Set-ItemProperty command does not directly allow the value type to be influenced. The command will do as much as it can to fit the value into the existing type. For a property with type REG_SZ, numbers will be converted to strings.

If a value does not already exist, a registry type will be created according to the value type:

• Int32: REG_DWORD
• Int64: REG_QWORD
• String: REG_SZ
• String[]: REG_MULTI_SZ (must use "[String[]]@('value', 'value')")
• Byte[]: REG_BINARY
• Any other type: REG_SZ

If a value of a specific type is required, the New-ItemProperty command should be used instead, for instance; if an expanding string must be created:

New-ItemProperty HKCU:Environment -Name Expand -Value 'User: %USERNAME%' -PropertyType ExpandString 

New-ItemProperty will throw an error if a property already exists. The Force parameter may be used to overwrite an existing value with the same name.