Sounds like you probably need to run a offline mode virus scanner. At this link you can download ISO image to burn to cd and boot from them. If you scroll down towards the end of the list and just before the comments section there is 2 more pages to browse to more brands.
It sounds like you got a very destructive virus payload and that it trashed the MBR (master boot record). MBR is the first sector or section on the drive that tells windows how to boot and which file to look for to boot. Be sure to try the offline virus detectors first before attempting a MBR fix. Reason being is even if you fix the MBR this virus more than likely resides in a start up type location. Be it in the start up folder, msconfig, start services, registry /run area or some other file like a .ini file, it may even overwrote a system file with it's own. Without the virus actually being removed and damage repaired it will more than likely trash the MBR again on next boot up. If you do boot into the Windows OS successfully you will need to go over all those key areas where the virus resides and disable them etc if it's even possible. The first thing that these viruses do is disable the virus scanner & takes away your ability to fix stuff. IE: the ability to run CMD.exe, It does the same for regedit.exe etc. It will then make sure it starts up in the start up files, It will probably wipe out all the restore points on the drive, trashes the MBR so you cannot get to safe mode or even boot in this case which was probably it's ultimate goal. You may have to just restore the system completely as the damaging payload was to great.
to repair the MBR you set the bios to boot from CD/ROM first, then you boot from the windows disc to get to recovery options.
This is link shows the procedure for XP & Vista/Windows 7.
Once you have everything running again I highly suggest changing some passwords unless you had them passwords stored in Firefox under the master password feature, as the file itself is 256AES encrypted. Also, you should have a backup solution plan. Some sort of HD imaging software that clones the HD and stores it on a separate USB HD. First line of defense if the Virus scanner, Second line of defense is a system backup. I suggest retail copy of Norton antivirus or COMODO. Many dislike Norton as it installs itself to deeply into the system and takes over control of the Firewall etc, or it uses to much ram bla bla bla. There is a reason why it does this as it has to protect itself from viruses like the one you have.
Edited by technonymous, 17 September 2013 - 09:25 PM.