You could try the following:-
Start Menu/Help and Support doesn't work: Go to Start/Run and type in: helpctr -regserver
To reinstall Help and Support: Go to C:\Windows\inf\pchealth.inf. Right click and choose install. Have your CD handy.
Note: The folder is hidden by default. Go to Start/Run and type in: control folders. View: Show hidden files and folders and uncheck Hide extensions for known file types.
These usually work.