here is a piece of code I use in an API wrapper project I have:

Code:
Private Declare Function GetDriveType Lib "kernel32" Alias "GetDriveTypeA" _
(ByVal nDrive As String) As Long

Public Enum DriveTypes
    DRIVE_RAMDISK = 6
    DRIVE_CDROM = 5
    DRIVE_NETWORK = 4
    DRIVE_FIXED = 3
    DRIVE_REMOVABLE = 2
    DRIVE_NO_EXIST = 1
    DRIVE_UNKNOWN = 0
End Enum

Public Function GetVolumeType(ByVal RootPath As String) As DriveTypes
    If Right(RootPath, 1) = ":" Then RootPath = RootPath & "\"
    GetVolumeType = GetDriveType(RootPath)
End Function
Tom