Windows 98, ME, XP, and 2003 have a program for changing settings in Windows.  It is called the System Configuration Utility, or msconfig.  The top button will run this program.

If these buttons are disabled, RegVac could not find the System Configuration Utility on your computer.  This is because you have Windows 95, NT, or 2000, or it is not in the proper place.  It will run in these other versions of Windows, so if you want to use it, you should be able to find it on the internet.  The System Configuration Utility allows you to disable settings to troubleshoot problems. 

The second button in this section will delete the disabled settings, removing them to Undo.

 

The "Clean Disabled Keys as part of Automated Scans" checkbox lets you include the cleaning of System Configuration Utility keys in the automated scans.