Recovering a corrupt windows system

Start initially running the anti virus and anti malware scans to correct any problems and then survey the damage.

If the disk is damaged the run scandisk to correct then - information on how to do this is at
http://support.microsoft.com/kb/156571

Then try doing a Windows xp system restore back to before xmas which will restore the system files and drivers back to before you started having problems - information on how to do this is at http://support.microsoft.com/kb/306084

If that doesn't work try and use the system file checker (sfc.exe) to restore any corrupt system files - information on how to do that is at http://www.updatexp.com/scannow-sfc.html

Failing that you will need to reset your laptop back to factory settings and restore the whole windows disk. Information on how to do this should have come with your laptop (it differs from supplier to supplier) - make sure however that you backup any data first as it will wipe the disk.