With the exception of Windows 3.x and Windows NT, all other Microsoft Windows Operating Systems can boot up using a feature called "Safe Mode". When you start your computer in Safe mode, Windows only loads the barest set of specific components that are needed to run the Windows operating system itself. You can use this 'diagnostics' mode to do things like modify the registry or load or remove problem drivers and software.

How to reboot a computer in Safe Mode varies a bit with each version of Windows. A good set of instructions covering these variations can be found on the following Symantec site:Tip: Because most spyware cannot be removed while it's running, it's best to try and run your spyware removal tools in "Safe Mode".