Just found this - tweak - at com-central.net FSX tweaks
How to perform a clean boot procedure on a Windows XP-based computer
To perform a clean boot procedure on a Windows XP-based computer, follow these steps.
Note You may experience a temporary loss of some services functionality when you follow these steps. Restoring the settings restores the functionality, but may result in the return of the original error message or behavior.
1. Click Start, click Run, type msconfig in the Open box, and then click OK.
2. On the General tab, click Selective Startup.
3. Under Selective Startup, click to clear the following check boxes:
• Process SYSTEM.INI File
• Process WIN.INI File
• Load Startup Items
4. On the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All.
5. Click OK, and then click Restart.
