Hey guys...first time poster here. I apologize for the length of the post but I have done a LOT of diagnostics work and can't figure this one out. Specs: XP Sp2 32 Home Edition Intel P4 2.2G dual core Nvidia geforce 8600GT =( 4gigs dual channel ddr2 twin2x from Corsair Seagate 160 sata HD and new Seagate 500 sata HD intel dg35ec mobo ethernet card (don't remember off the top of my head) no additional sound card 450w PS (came with case Xion II (xionusa.com)) Built about 4 months ago...no issues until now. Drivers installed right after build no updates/rollbacks. Issue: Started a week ago when I bought company of heroes: opposing forces. I want to stress that there has been no issue like this until the installation of the game but it has since infected the overall performance of my computer which makes me believe it's simply coincidence. The game worked fine for about 2-3 days and on day 3-4 I would get periods of intermittent lag. It's clearly hardware lag...the game FREEZES entirely and the sound goes into what seems like a 1ms loop (it's godawful to hear when there's an explosion). It tends to do so when the PC is being stressed...ie: artillery is landing on a lot of units. After days 3-4 it got continually worse to the point where unvieling the fog of war would cause these spikes. The cutscenes and DivX videos in game got really bad too. The sound after the spikes would be FUBAR for anywhere from 2-30seconds hearing sometimes nothing...other times scratching sounds...and sometimes it seemed to randomly play a few sounds here and there (gunshots from one of 4 squads or random ambient noises). At this point I tried underclocking my memory bus speeds and it fixed the problem for a few hours...then it slowly came back. I noticed that after the problem occured...youtube videos would experience a similar sound crackle for a few seconds and my mouse and video would cut out for a split second while opening programs or sometimes doing nothing at all. (The mouse would freeze as if it were in the game as it was being stressed and experiencing this lag. It gets caught in a position and completes user input after the lag spike. Not as frequent as in game but it still happens out of game and in other programs). I also noticed the windows loading screen with the blue scroll bar now flickers at a certain point while loading windows. The load got progressively longer and longer as well. When windows would boot the blue Welcome screen would sometimes stay up longer after the traditional windows sound would play. I ran benchmarks and certain tests (memtest included) and came to the conclusion that it was probably my hard drive. I bought a new 500gb HD and did a fresh windows install on it. I updated all drivers (bios/vid card/chipset/etc) and reinstalled COH. Well it worked for a while now the problem is occuring again. I can play the game until it is stressed again with many units and artillery firing down etc..the hardware lag will come and it will go to a BSOD and reboot. The error message warns about new hardware etc etc. I was also getting the BSOD on the old hard drive but not as frequent. Before the new HD and install of windows I noticed my CPU usage was spikey. 2-12% during idle and in game 60-90%...and when the hardware lag would come my cpu usage would drop to 0%. I ran another memtest which reported nothing. I ran a few CPU stability tests including prime95 which seems to rule out my ram and cpu. I have a feeling it's the on board sound card which ultimately means i need a new mobo. Oh yea and XP 32 limits the amount of ram allowed on a system (the 4gigs only registers as 3.25 this is nothing new....but when i run memtest it suggests running several instances to account for all your ram. I opened 4 running each at 1024 and the 4th at 256. The 3rd 1024 memtest stopped responding before the test could initiate. I don't know if this is significant.) I have also researched a lot and come to the conclusion that this may be a problem with my ethernet card? It's not usb it is ethernet but I've heard reported similar problems with usb modem cards. Any thoughts/responses/suggestions will be very much appreciated. Thanks in advance! PS: I later tried Counter-Strike and other video games that used to run fine...they now also experience similar symptoms.