Converting the FileSystemObject's FileSystem Property
Definition: Returns the type of file system of the given drive, such as FAT or NTFS.
Use the DriveFormat property of the .NET Framework DriveInfo object:
$d = New-Object -typename System.IO.DriveInfo -argumentlist "C:" $d.DriveFormat
Here we called the New-Object cmdlet to create a DriveInfo oject, passing New-Object the -typename (the class) and the -argumentlist (in this case, the drive we want to retrieve information on). We then check the DriveFormat property on the object we just created.