How to troubleshoot a problem by performing a clean boot in Windows Vista

I thought this article will help people to troubleshoot slowdowns in the windows boot process:

http://support.microsoft.com/kb/929135

But it will only help in cases where services of installed programs cause the slowdowns.

You can disable startup apps and see if the slowdown is caused by one of them.

If a driver is slowing down the boot process, you can check if safemode works fine, because Windows will not be loading drivers (except the ones that are really needed to get the system up and running).