Reverend gave you the most probable cause to your issue, and the fix, so please keep us updated.
And for further information, to have the best system configuration and setup available, it is always recommended to do a reinstall of the OS, rather than an upgrade, with XP, it's fairly simple, just choose the format option when it asks where you want to install the OS, I typcially do the full format, rather than the quick as it rewrites everything, including the file structures. If that is impossible, the best way to do it, would be to clean install windows ME, then immediately afterward do the upgrade, run the updates to Windows XP, and sort out the problems as they arise.

Welcome to techzonez.
BB