Hi all, I recently purchased L4D on Steam. Played it for about 4 hours without one single issue. I closed the game, came back to it about an hour later, and when I went to launch it, Steam told me that there was a newer verison of the driver available (I had been running version 180.48). So I went to Nvidia's website, downloaded the newest drivers, ran the setup, and rebooted my PC. Everything started up fine. I loaded L4D, but it started to "hiccup" every 30 seconds or so for about 3-5 seconds. The game would completely stop.....then start again. No repeating sounds or anything. Just....whatever was on the screen. So I uninstalled and reinstalled the newest drivers again (181.22). This time the game will completely lock up my PC, and repeat whatever the last sound that was playing. The only thing I can do at that point is hit the reset button. So I uninstalled the 181.22 drivers, and reinstalled the 180.48 drivers. Same problem. Complete lock up with repeating sound. Alt+Tab, Ctrl+Alt+Del don't do anything. All I can do is hit the reset button. I started doing some research and found out that I should use a program called Driver Sweeper in Safe Mode after each uninstall, and that I should to the driver installs in Safe Mode because of my Antivirus software, and because of some aspect of the Windows operating system that can prevent required parts of driver installs from loading correctly. So, I uninstalled everything Nvidia related (except for my NIC drivers), rebooted the PC in to Safe Mode, ran Driver Sweeper, rebooted in to Safe Mode again (wasn't prompted to, but I did it anyway), ran the 180.48 driver setup. Rebooted in to Normal Mode, and launched L4D. Same issue, except I get far enough in to the level now where I think everything is ok, and then BAM! It crashes. :bang: I've repeated that last list of steps several times over the last couple days. But still nothing. I downloaded Riva Tuner to bump my GPU fans up all the way and to monitor my temp levels. I've checked the log files that are created with that app and everything looks fine. No temp spikes, or anything like that. Today at lunch, I decided to try and remove my NIC drivers as well as my Display drivers at the same time. So I uninstalled both NIC and Display, rebooted in to Safe Mode, ran Driver Sweeper for both NIC and Display, rebooted to Safe Mode, installed the NIC driver, rebooted to Safe mode, installed the 180.48 driver, then rebooted in to Normal Mode. This time, L4D loaded, I could start to play...then all of a sudden the colors on about 60% of the textures go all screwy (bright yellows, whites, blues), but the game is still running. Most zombies show up as dark shadows unless I shine my flashlight on them. Then they look normal. The game ran for about another minute, and then locked up the system completely with the (now familiar) sound repetition. I've been playing TF2 for at least the past 10 months without any kind of issue. Now, since screwing with my drivers, it crashes in the same fashion as L4D. So I know it's not game specific, and I've ruled out overheating. The only thing I can think of left would be software/driver related, and since the problem is unequivocally related to me messing with my display drivers, I'm leaning towards that. I am completely at a loss! Does anyone have any suggestions for me? :wanker: Thank you very much in advance. Sorry for the long post.