When working with the filesystem provider, Get-ItemProperty and Set-ItemProperty are rarely needed. For example, Set-ItemProperty might be used to make a file read-only. The following example assumes that the somefile.txt file already exists:

Set-ItemProperty .somefile.txt -Name IsReadOnly -Value $true

The same property may be directly set from a file object retrieved using Get-Item (or Get-ChildItem):

(Get-Item 'somefile.txt').IsReadOnly = $true 

The IsReadOnly flag affects the attributes of the file object, adding the ReadOnly flag.