You need to break down the security built in to XP for the consumer.
Try this
1. Log in as 'administrator' (or some other user with administrative privileges) on the PC.
2. Go to "Start" > "Control Panel".
3. Open "Administrative Tools".
4. Open "Local Security Policy".
5. Open the "Local Policies" folder.
6. Open the "Security Options" folder.
7. Scroll down and double-click "Network access: Sharing and security model for local accounts".
8. If this says "Guest only - local users authenticate as guest", change it to "Classic - local users authenticate as themselves" and press "Ok".
Why this may work: If your computer is using the "Guest only" model, all incoming share connections will use the privileges of the Guest user. The Guest user doesn't have privilege to access the entire C: drive. By changing to the "Classic" model, all incoming share connections authenticate as the user making the request (or another supplied username), and this non-guest user can be granted privileges to access your C: drive.
Alternatively, you could try sharing your C: drive to the Guest user. This would be horribly insecure, even if Windows XP allows it (and doesn't ignore it). Not recommended.
