Toshiba laptop hard drive recognized initially, then not

[ndunda]

None of the hardware has been changed in my Toshiba satellite P25 series notebook. A while ago, it had a virus so I reformatted it with an xp disk. The computer worked just fine, restarted as I installed drivers. Then when i shut it off it said i had no hard drive.

I tried to use the recovery disk, but it stalls.

When I go into the bios initially it recognizes the hard drive, starts to boot and then goes to a black screen saying windows did not start successfully and to choose how to start windows. Whatever choice is made, the computer begins to start, then a blue screen flashes and goes back to the Toshiba start screen. At this point in the bios setup the hard drive is gone. And if I try to start up i get a cycle of PXE-61. Is this hardware or bios??

[Sharedoc]

I suspect the master boot record has corrupted on the hard disk.