HUGE problem......X_X

Ok so today i was doing a routine hard drive clean up and since certain things take a while to run, i left the disk cleanup tool running before i left the house. when i got back, EVERYTHING was gone and i mean EVERYTHING. well, everything but internet explorer, random folders (no files inside), and the recycle bin. I also had about 6 windows up saying that windows files had been replaced with unrecognizable ones and i needed to insert the windows xp sp2 disk to reinstall them. Upon doing so, it would not recognize that the disk was in, although the auto-run did start but i couldnt see any words, just buttons. I restarted, hoping to do a repair since i couldnt get to the system restore, and it wouldnt let me boot into windows, it gave me this message: Windows could not start because the following file is missing or corrupt: <Windows root>\system32\hal.dll.

I tried booting from the XP disk but it asked for an administrator password which doesnt/didnt exist before today. Im guessing that it got a virus because my firewall was down for about 2 minutes while it was updating/reinstalling.

Is there any way that i could salvage my files or is everything gone for good?

Also, just to make sure i looked in My Computer and the C: drive was totally empty. Major bummer

 

i dont have another drive so i think im just stuck with a reformat as my only option If everything is gone anyways, there really isnt a point to trying to fix it....

 

i tried the repair install but it asked for a password that i never even made I tried possible passwords that i would have made it if i just forgot about it but none of them worked