hi may nedd to get a external dvd rom or install windows on a thumbdrive, depends on your computer knowledge
http://blogs.technet.com/aviraj/arch...umb-drive.aspx

Usually, Last Know Good Configuration will resolve the problem; if not, tell us more about the problem. Please give careful though to the following, as it will determine the next step int he troubleshooting process:

Are you using, or have you installed any remote control software?
Do you login to a workgroup, or domain environment?
Does your computer use biometric, or other third-party login software?
Were any device drivers altered just before the problem occurred?

I suspect a corrupt, missing,or replaced Graphical Identification and Authentication (GINA) DLL. GINA is a component that Winlogon.exe loads. If it is no found, it tries to find the backup. If the backup can't be found, the error is generated. This may require an XP CD.