Thank you very much for your post Kage.
I don't think the problem has to do with the SATA drive (not sure what it is though - I am practically computer illitterate) because I was able to unpartition the C and D drive before I brought my pc in for repairs. The only reason I brought in my pc for repairs was due to the fact that I had unpartitioned the C and D drives and was re-installing Windows XP but had not inserted the SATA drives whilst installing windows, thus corrupting the hard drive.
Once I had brought my pc in for repairs, the salesman told me they'd set the BIOS to the standard mode so I wouldn't have to use any extra floppy disk when reformating my pc. The problem now (I believe) is that the change they made in the BIOS disabled the feature that allowed me to unpartition the C drive. Now I am unable to clear Windows. I can only unpartition the D drive at the moment.
In concern to the RAM, I am hoping that it's in working order since everytime I bring my pc in for repairs they check each individual hardware piece before actually fixing any problem I may have. So far I have brought my pc in for 2 repairs.
As a side issue, the blue screens I got always produced different error messages. Here they are in order:
1) A process or thread crucial to system operation has unexpectedly exited or been terminated
Note error 2 occured when I turned my pc of via the power supply and rebooted it. Error 3 occured when I restarted the pc right after problem 2. Problem 4 occured when I manually rebooted my pc because I had disconnected my mouse. All these problems occured when the pc was booting up, except problem 1 which occured spontaneously when I was playing a pc game.
Any advice (particularly with setting the BIOS to allow me to unpartition C) will be greatly appreciated