Ok...I'm pretty new to the ins and outs of PSUs so I will try and give as many details as I possibly can about my PC and what I have tried so far to sort out my problem...please bare with me. Firstly, my PC runs fine, it is only when I play a game that the black screen loop sound problem happens...it is not even a power sucking game like warcraft or CoD2, it's Medal of Honor spearhead which is about 4 years old now...anyway, my specs.. INTEL PENTIUM 4 560 3.6GHZ 800mhz FSB/HTT/1MB 2048 MB DDR400 PC3200 (2x1GB) ASUS P5P800: DUAL DDR, S-ATA, 8X AGP, 5 PCI, ATA133 ETC SATA 250 GB HARD DISK @ 7200rpm 16mb cache 256MB GEFORCE 6600 8X AGP + DVI + TV-OUT SoundBlaster Audigy 4 7.1 Pro + External Kit (breakout box) 550w PSU (warranty replacement for a 500w that died) generic now a little history... I bought this PC about a year ago and it came in quite a small case that I was not happy with as it was locking up on startup because the case was overheating, took the side off and it started up fine...I had the choice of sending the whole thing back (and waiting another 3 months because the company that built the thing couldn't work out why it was crashing in the first place) and get a new case or buy one myself and do it...so I bought this (my link) Thermaltake case and installed everything. It worked fine for about 3 weeks until I started getting random crashes when playing Medal of Honor. After many many hours of research I have unistalled/reinstalled the game, did a format, used driver clean pro, reset my cmos, updated my bios, ran memtest for 11 hours, optimised my airflow by taping back all possible cables that would disturb it...I've cried, shouted and bored my girlfriend to almost suicide with my rantings about what I've done. Now I'm running this thermaltake PC with 7 fans all in all (including the graphics card fan) with the side off and it still crashes...I have to open a window to even get it to run at 800x600 medium settings in the game...I found my cat on the window ledge of our appartment last night, and being a few floors up I pondered whether he was just looking or was ready to jump because of my obsession with this!! I have done a front and rear fan speed check in bios and my fans are running a bit below par? The front fan is running at 1328rpm and the rear is 1288rpm...both fans are supposed to be 1400rpm. I have also noticed a hotspot on my graphics card right in the corner next to the motherboard when I play the game...I have a (my link) Gigabyte G-Power Cooler Pro CPU fan which sticks out about halfway across my rear fan...could that be disrupting airflow and therefore causing the hotspot? (I do have a pic of the inside of my case but my digital camera is not being reconised by USB at the moment ) I'll post a pic tommorow if anyone needs to look at it? I'm basically at my wits end with this problem (so is my girlfriend and cat)....I'm really leaning towards the PSU, I did think that 550w was ample for a machine of my size but considering that I am running a lot fans and externals off the power supply it may not be and I'd like someones second opinion...like I said I've never really dabbled or thought about PSUs as the problem...I even returned my graphics card under warranty because I thought it was flakey...could someone give me their opinions and save a poor woman and a cat from an obsessed temperature maniac?? thanks.