if nothing helped, try this:

1. Start -> Run
2. Type "cmd" then hit enter.
3. Copy and paste the following into the command prompt:

net use * \idisk.mac.comyourusername * /user:yourusername

replace yourusername with your actual MobileMe user name.

4. It will prompt you for a password, enter it in.
5. Wait about 15-20 seconds, maybe more.
6. It will confirm that your iDisk has been mounted and it will tell you the drive letter.
7. You can now access you iDisk the same way the iDisk Windows XP Utility would.