Make sure you are an Administrator in XP.
If you are running your installation on a Windows NT
4.0, 2000, or XP, you are more than likely the administrator of your computer.
Follow these steps to confirm administrative rights on your home computer:
1. Select Start > Control Panel > Administrative Tools >
2. In the Computer Management dialog, click on System
Tools > Local Users and Groups > Users.
3. Right-click on your user name and select Properties.
4. In the properties dialog, select the Member Of tab
and make sure it states “Administrator”.
Note: In Windows XP Home the Administrator Account can
only be accessed in Safe Mode.