...and then there's ME's "Restore" function. Sometimes works well, but not always.
See if you can find a Restore point far enough back before the problem started.
And undo anything you did just before the problem appreared such as uninstalling a new program (application or game) or uninstall a bit of hardware.
If you're using McAfee for Virus protection, you'll need to visit the McAfee Web site to download a special patch. Later updates to the basic suite were incompatible with ME.