On your win7 disk is a folder called "Boot"... in that folder is a program called bootsect... you will have to run this from a console in safe mode, but just follow the instructions it gives and it should be able to get rid of this last remnant...
If not, it may come down to replacing your hard disks...
Next stop using nod32... try the emergency kit I linked you to in a previous message. The Kit installs on a flash drive (so it cannot be infected) and run a full scan of your system once a week and when you think there may be aproblem. Many AV softwares do not check boot sectors ... the EK does.