fix computer errors

I’m getting blue screen errors but only when I’m in the process of downloading a program. I recently had some issues with my notebook where when I tried to type something in Word, the program would terminate. Then my firewall turned off on it’s own and wanted to turn on Internet Connection Sharing before I could get to the firewall. Everytime I said no, it would terminate as well. So I assumed it was a virus, after doing a sweep and getting rid of some suspect things, I deleted the partition and reinstalled the operating system (XP). I then installed the drivers in the order the disk stated.
The OS was outdated, SP2 and some of the drivers, e.g. my video driver, would not work. So I went to Dell’s website and re-downloaded the drivers for my specific laptop, including an updated BIOS. When I start to add other programs, I get the blue screen errors. Flash player, firefox, and silver light downloaded fine. Office and lava soft would not.
I haven’t tried to re-download the OS because I’ve updated it with SP3 and everything is fresh. I’m assuming it’s one of the drivers I download but I have no idea which or how to go about figuring it out. I’m thinking I need to do the entire process over but I’m also thinking there has to be a way around that.
Two of the error messages that I thought to write down were:
0×00000077
0×0000007A
Also file names mentioned were:
atapi.sys
win—-.sys
Also got error codes like:
Error Code: 0700-0750
Msg: IDE device failed
Error Code:0700:1344
Msg BLock: 2953321
0700:0244
3239679
Please help!!!