Reformating the Computer from Sony

Hello, I have a Sony Vaio VGN-N320E That originally fell prey to Viruses. Since that time I have been trying to reformat it. The Startup partition within the drive apparently became corrupt as well. I ordered the disks and tried to use them to no avail after 4 attempts with and without the assistance of Vaio tech support it was decided that the disks that they had sent out were bad, so they sent me out another set. From there, things just went from bad to worse. When I tried the new disks the program itself determined that my drive was too small or did not exist. So, after talking to Sony again, and specifically being told that it did not matter what drive that I purchased other than it needed to be a SATA Drive, I purchased a 250 Gig Seagate Sata drive. Again I tried to install from the original disks and again the program told me that the drive was too small or did not exist. Because it was a brand new 250 Gig drive I was dumb struck. I tried repartitioning the drive to its original specifications and the same thing occurred, so back to Sony. Now I was asked if the drive was an advanced formatted drive, as it turns out of course it was. So with that I purchased another drive exactly identical to the original. Now again the same thing has happened. It says that the Drive is too small or nonexistent is the error. Does anyone know the answer to this one?