Greetings,

I have a Dell Dimension 8200, p4 2.4 Ghz processor, geforce4 ti4600 128 mb vid card, and 512 RAM.

I've been having video problems for about a month or more now.  I notice these problems in games I play, especially Unreal Tournament 2004 (single and online mode) and Dark Age of Camelot.  The main symptom is my screen will randomly freeze up for 10 seconds, after which there is a white flash and I'm returned to "normal" until it happens again.  I've started noticing other graphic glitches that are often a preelude to a freeze - odd blinking polygon shapes and objects that look like they're having trouble rendering.  The worst-cast scenario is my screen will go haywire, some parts will freeze while other parts blink uncontrollably, and I have to force a shutdown as I can't do anything.  I've only noticed these problems in these 2 games (maybe some other minor glitches in other games), but they are the 2 I play the most.  I've had this comp for over a year, and it's run DAoC without a hitch the entire time.

On a side note, I had to replace my case cooling fan.  It started making terrible noise, and I noticed it constantly starting and stopping.  I replaced it with an Antec 92mm fan from CompUSA and it seems to be operating smoothly and fits perfectly into place.  However, I could not plug it into the adapter on the motherboard (where the original fan was plugged) because the 3-prong wouldn't fit into the seemingly fixed adapter.  Instead, i used a spare 4-prong plug from the power supply to run the fan.  As the original fan began failing, I began to receive "Alert! Previous Fan Failure" upon start-up.  Even with the new fan, i still get this message.  I should also note that my video problems coincided with the first fan's failure, and the exact same problem exists with the new fan installed.

I have tried:  upgrading video card drivers, updating BIOS to A09, updating intel chipset drivers, scanned the C drive for bad blocks, ran Spybot, ran Norton's Scan Disk and update all virus definitions regularly, disk defrag.  There may be other small tests that I've tried, but I can't remember them and none showed any problems.  I have not tried re-installing windows and I haven't dusted the interior of the comp with a pressurized air canister (though I opened it and dusted the best I could).  I've never powered the computer on while the case was open, so I haven't been able to see if all fans are running.  Reason I haven't is I'm somewhat of a computer novice on the heavy technical stuff, so i wasn't sure how to do this safely.

Any advice you can give me is greatly appreciated.  I've reached the end of my ability to troubleshoot.  In phone calls and e-mails with Dell, they seem to be missing my main problem, and they think replacing the fan again (with a new version of the original) will solve the problem.  I'm guessing the problem goes further than that - like the video card or the processor.  Thanks in advance for your help.