I want to run down what I've been going through and what I think solved it to see if this makes sense,.
First about a year ago I got Windows 7 64bit for my pc to change from vista, from that point i've had random crashes, 90% of the time in 3d video games. To fix this I did the following (at the end I'll tell you what ended up seeming to solve it so far)
1.) Drivers - I tried Nvidia drivers 192.61 - the current driver which now is 270.01 beta or something but it only was up to like 220.00 something when I had that card,
2.) I Went through every windows service one by one to determine if it was that.
3.) checked my temperatures and my average temp was like 25 - 30 range, my cpu never goes above 50, and my video card runs at around 40 In GTA 4 I managed to get my cpu to 55, and my GPU to 42 but thats about it.
4.) I memory tested the crap out of my ram, over night several times with no problems
5.) Windows event logs recorded nothing but the fact that I hard booted it.
6.) I replaced all the cords inside the computer I could and changed the power outlets on some.
7.) I thought it might be my hard drive, I tried windows on both and it still froze, I added a new one, still crashed.
8.) I thought because it seemed like a video crash it was my video card so I replaced that but no. it wasn't that.
9.) checked for malware, trojens, spyware, viruses, worms every possible thing nothing, and since I formated and searched for MBR infections there was nothing anyway, It happened clean install and not clean install.
I tried at least 100 other things but never got a result until.
I changed the memory I had into single channel mode rather then dual channel mode as I had before I installed windows 7 (By changing the slots they were in on the motherboard) , Is it possible I have a bad ram slot? could that have been what caused random freezing? I've never had one so I'm not sure of the symptoms. See with my new graphics card i should be able to play GTA 4 at max settings without lag, before I could not and it would lag, however the second I swapped modules it seemed the game ran seamlessly.
Freezing on Windows 7 is most often caused by memory problems even though the memory may pass all memory tests. This is (I think) due to the way Windows 7 does DMA transfers from the disk controller to the memory the memory timings being much tighter in this instance. I have had computers where only the replacement of the memory to a different brand would cure the problem. Sometimes the problem can be “cured” by only fitting one stick of memory. Interestingly Windows XP or Vista on the same computer do not suffer from the same problem.
Ya I had no problems on Vista at all but right when 7 was installed I've had random freezes. So in essence your saying turning DMA off will also fix the problem. I know how to disable it on cdroms, and hard-drives I can find my memory under device manager, its probably in hidden devices.
OK first off how old is your motherboard & processor... second did u check for blown caps on the motherboard? besides dust build-up. If the board is fine then look towards ram... and yes a RAM slot could be bad! do you have 2x or 4x ram slots.. try diffrent slots with only 1 stick of ram, did u use memtest in DOS or MSDOS?... ram is cheap. might wanna try new kingston chippp u changed video card? PCI-E? and new drivers? besides chipset drivers for motherboard for your OS? best to get drivers from the motherboard makers website if u dont have the disc. malwarebytes is a free also very good program to see if your AV sucks and your infected after all that i would use testing tools to test the power supply see if its not giving enough power most motherboard makers give u free tools to see if your gitting correct volts to the +12.v - +5.5 +3.5 -5 and 2 others i believe. u said u changed to new HDD?? so u ruled that out unless u ghosted your OS to the drive insted of new OS installed. that is just about the sum GL