Newbie needs help:GeForce5700le drivers

[drwngflies]

I hope I have enough info to relate to my problem. I have a budget Systemax PC, unknown brand M/B,WinXP OS,Intel Celeron, 768MB DDR RAM,
19 GB free Mem, GeForce 5700Le 256MB Graphic card, installed with the driver disc supplied w/ card. I downloaded what I thought was an update from Inno3D, and saved it to program files, but to no avail.
My isue is that now, the curser*(sp.) jumps when I move my mouse, and the
screen freezes then releases when I try to play games. . .ie:Colin McRae Rally,etc.,nothing like Doom or Halo tried yet. I do not wish to try a Beta prog. if there are alternative solutions. Do I need to move up in processors?
Is the celeron too slow? I also am getting buzzing noises sometimes from my speakersC Media AC97 audio).
I have had a few Stop errors/Blue scrn crashes too-points to driver problems
(nVidia): Stop:0X0000008E
Does someone have a remedy? Thnx 4 any input. Stumped. . .
Is it worth Overclocking this card? Or is the Celeron holding me back?