Strange but true, there are times when we decide to get rid of some virus or a worm by reformatting the system but even after formatting the PC we are shocked to see the virus back in our computers. This is what happened to my friend who formatted the PC just to get it cleaned but the problem was still there.
I must confess that there is no better way than preventing the virus to enter the system, to protect our PC from viruses but there are viruses (rare but still there) that do not get removed even if we format our disk. It may also interest you to know that these viruses may also infect the BIOS and/or the boot sector. So if you feel that your BIOS is infected then only reflashing it is the option available.
So these are the steps that you can do to ensure the removal of virus after format:
1. If you are just formatting the PC to delete the viruses then make sure to format the complete system and not a single suspected drive as most viruses come back from other drives.
2. While formatting the system through the Windows CD, perform “delete all partitions” to clear all data that contained the worm.
3. If this format still doesn’t work (I don’t think it would happen) then you should perform a Low Level Format on the disk that will surely erase everything stored on it. Read this to know better.
Any of the methods listed will surely solve your problem.