I am running Windows XP Home SP1 and recently, about a week ago I encountered a serious problem with my PC. When I boot up and Windows reaches to the 'Windows is starting up' screen it hangs. Occasionally, it will reach to show all the User Names but I cannot click on them or even to 'Shut down this computer'. The only way I am able to access my account is to press F8 and select 'Use last know good configuration'. Does anyone have any ideas? I tried System Restore when the problem first emerged but the problem recurred and now it is too late to restore that way back then. Thanks in advance for any help.