Windows 7 frequently freezing

Ive been having some issues with my rig, wondering if any one out there would lend some aid. Computer will freeze up about 5 times a day relatively evenly spaced out, it started happening at random on previous install, went away for a week on the fresh install but started up again soon after. No bsods ever, computer runs great other than the freezing. Mouse still moves when frozen all programs go out of focus but the desktop icons still highlight when the mouse goes over them. I haven't the faintest idea whats wrong, all temps are low, cpu and ram are not overclocked, gpu has been for about a year but its been stable. Install is about a month old, 64bit running on
i5 760/xigmatec s1283/ idles at 20c never goes past 30
gigabyte p55a ud3
gskill ddr3 ripjaw 2gigsx2 1600 cas 9
bfg 8800gts 512 40-50c at 770c/1000m
3 western digital 80 gig hd's in raid 1
1 maxtor 200gig
1wd 80 gig laptop drive
vx550 corsair
no errors on memtest or prime 95. It has had Norton av installed the whole time, it has reported no issues. Ive been thinking its got something to do with 64 bit compatibility but no one program is indicating that just total lock ups. Thanks for any help you can provide.

Have you ran it through the usual gambit of HW tests? Memtest86+, IBT, etc?
Also, what about programs you have installed...might check your msconfig for something running in the background.

Very odd though...

Have only run it through memtest and prime95, nothing running out of the ordinary in ms config, all is sorted. Quite the mysterious problem.

Well that is strange. Hows your HD health? Ran a full chkdsk for errors on all sectors yet?

With my rig I've noticed that it freezes more (once every two days if I have it running non-stop) as opposed to when its OCed. For my rig I am sort of guessing that it might be RAM issue. I have the Corsair XMS3 1600. When I its OCed the ram is in the 1400mhz range, when not OCed its a little over 1000mhz which I assume it does not like. I am not sure that this is your cause of the problem, or mine for that matter, but it does fix my problem while OCed + it keeps my room nice and worm during the winter

Hopeful someone else can comment if it can truly be a ram issue.

A freezing like that sounds like something is corrupt in the operating system. Have you run

sfc /scannow <---- checks all the windows files to be sure they are intact and not corrupt

CHKDSK /r <--- takes over night to check the harddrive for surface errors and corrupt files/folders

Can you activate TaskManager once it freezes? If so are there any apps under Processes that are taking lots of resources (huge memory usage or CPU near 100%) - if so, delete or reinstall that app.

Otherwise, the next suspect is new drivers/apps installed, then RAM followed by PS, and then harddrive - I would do a backup just to be safe and then experiment.

I would remove one stick and see if that solves the problem. If not, swap sticks and try again. Unfortunately Memtest doesn't always find memory problem, especially if the RAM is just starting to fail. Swapping the harddrive out and the PS might solve the problem as well.

Some hardware does not play nice with Windows hibernation, I would try as a test, changing your power-options to remove hibernation features.

Thanks for the responses, ill have a go at whats been suggested asap.