I wonder if you're using NTFS on that curmudgeonly Desktop. If you are, you can attack the Security (in Properties) as well as the Shares. Assuming you are logged on as the Administrator, you can give all Users ("Everyone") all rights to the whole PC. If it's using FAT32 this option isn't available. When you are setting up the Desktop's drives you need to propagate all permissions to Child objects as well.
There are other default XP restrictions to grapple with. If you are logged on as Administrator and not with a real name (such as Keef), certain folders are barred to visitors from the Network. They are Documents and Settings, Windows and, from memory, Program Files. (Don't hold me to the last one.)
I wasn't sure about Richard's idea of deleting the $ in the share. The default share for all drives is "$"something. Normally this share is invisible to all users except Administrators and then only for Admin purposes.
A User-friendly share name is what is needed.
[Oops, sorry Richard, overlapped with you there!
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