random short term freezes and judders

My computer often will spend 30ish seconds frozen or running horrendously for no apparent reason. It doesn't seem to be related to the stress on the CPU since i'm currently running an OCCT Linpack stress test at 90% RAM use and i'm not having any more problems than normal, maybe less. I've run a memory check, both windows diagnostic and with "memtest" and they both say the RAM is fine. I've run Orthos stress tests for well over an hour and the current OCCT test has just reached an hour and nothing has been returned.

A good example of what happens: Battlefield BC2 runs perfectly on full spec. On Empire:TW it all runs smoothly even on massive battles with 10'000 troops all fighting at once but when i try and interact with notifications at the start of turn it sometimes freezes for a bit and then runs again, similar problems in Left 4 Dead 2 and Warhammer Dawn of War 1.

I'm running Windows 7 on a 2.66GHz i7, 6GB RAM, nVidia GTX260, MSI X58M

Any ideas for what i can do to try and solve it? Or at least diagnose the issue?

it seems to be getting worse, it completely freaked out twice in about 5 minutes, i started running a low stress test and while it's running slowly it seems to be more stable.

First you have done a "double post". Also posted in Hardware.

Some games have been causing issues with Windows 7, actually it's the reverse. Maybe there's someone here who can help.

I think this issue is caused by the amount of processes/programs you are running. I don't have this problem much anymore, but when I run too many things at once while playing games, the games will start running rather horribly. Also you might want to bring any recent overlcocks down a little bit, but I'd recommend checking your temps.

I did that because i thought it could be either a wondows 7 issue of a hardware issue and want to get opinions on both.

it seems unrelated to the background processes, sometimes it'll freeze up with nothing more than media player, internet and MSN running and others it'll work with fine with allsorts going on.

I'm currently not overclocked, i thought that might be the issue so returned everything to default settings and it's not overheating, it never gets above about 40C apart from when stress testing when it reaches 78, still below the max safe temp for an i7.

everything runs fine, it freezes and freaks out, and then runs fine again rather than just generally not performing well.

Go into the BIOS and disable everything related to dynamic clocking: C-STATE, EIST, SpeedStep, C1E, and any similar option. See what happens.

done that, as far as i can tell at least, and it's had no effect. To be sure it wasn't an issue with multitasking i ran Warhammer Dawn of War with as little as possible in the background, even disabled anti-virus and network, and it made no difference.

My GPU has just started acting up, no idea if it's related, but even in POST screen i get red dots all over the place, it's not the monitor, any idea if the two could be related? i'd also assume it's not driver related since it occurs in the POST screen as much as in windows.

Do you have an SSD?

//EDIT: Red dots indicate a dying GPU or underpowered/dying PSU. An underpowered PSU could create all the symptoms you're experiencing.

never heard of an SSD, unless i just don't recognise the acronym.

i've borrowed my flatmates PSU, i'll try that now and let you know what happens, fingers crossed

just plugged the new PSU in, the graphics are unaffected but so far the freezing seems to have stopped, i'll give it a bit of work to do and see if it keeps surviving but it managed more than 5 mins of game time perfectly smoothly so it's promising.