lappy infected with virus

[NiluGeek]

my lappy is being infected with virus, it duplicated the existing file in which it resides , it does not allow to format hard drive.suggest any free antivirus software, wht can be done to format hard disk

[Kiran.dks]

avast! Free home edition.
http://www.avast.com/eng/avast_4_home.html
Don't forget to scan in "safe mode".

[ravi_9793]

Download kaskersky antivirus.30 days trail
http://www.kaspersky.com/downloads

Before scaning:
1) Turn off system restore
2) Scan in safe mode with one good antivirus and two antispyware.Remember, both should be updated.

If possible perform online scan.You can find few here:
http://www.techiehome.org/viewtopic.php?t=512