My dell inspiron is not working

Its not a big problem,first don't panic.just follow the steps i m telling you-
when computer give options like safe mode,safe mode with net working etc.enter on safe mode
after that if windows starts thn run your antivirus installed in your computer and if u dont hav antivirus then install it using pendrive or cd and run it.
after full scan od the system restart computer again.
if problem persists then again start your computer in safe mode and cut all the importand data from your c drive and paste it on d drive or e drive and reinstall XP or VISTA but remember while installing XP OR VISTA computer will ask you to format whole computer or the c drive only,u only format c drive.
tht's it

and always have one good antivirus installed in your system and update it regularly.

cheers