Random Freezes

I've already tested the memory with no errors, im sure its not a software issue as I had these freezes on windows 7, and yet upgrading to windows 8.1 on clean install didn't fix the problem. What else could be causing the problem. They happen quite rarely, of 2 week intervals maybe, unpredictable, so its hard to tell whether it stops...

What are your system specifications?

Just for thought - even though the memory test came out with no errors, there can be memory compatibility issues with some motherboards.
For example, 5 years ago I did a small gaming build, here are the specifications:

Motherboard - ASUS M2N68-AM Plus
CPU - AMD Phenom X4 9850 2.50 Ghz
Memory - Corsair 2 GB DDR2 800 MHz
Hard Disk - WD 250 GB SATA II
GPU - NVIDIA Geforce 210 512 MB DDR2 - Old version of Geforce 210 before DDR3 release
Power Supply - XION 400W power supply
DVD Writer - Liteon DVD-RW writer

When I first got the build done, I had nothing but issues. First problem was I had the wrong CPU, as this motherboard would only support 95W CPU's while mine was a 125W CPU. Anyway, I would have "Memory Management" bluescreens, and random freezes on the system under Windows 7 Professional x64. I changed my CPU to an AMD Phenom II X6 AM3 95W 2.70 Ghz. This got rid of the CPU problem, however, the memory management bluescreens still persisted.

I did some research, and it says that these bluescreens could be caused from faulty RAM, or other faulty hardware, such as the Graphics Card, or could be a bad memory controller in the CPU. With having 2 different CPU's, I ruled out the possibility of a bad memory controller.

Next, I changed my Geforce 210 out with an ATI Radeon HD 2400 Pro. After I installed this, the bluescreens got worse, with the same Memory Management Error. So, lastly, I decided to change out the memory with a different brand.

I bought a PNY 2 GB stick 800 Mhz, and installed it in my system. My motherboard brought up that there was a different memory module during post, and I had to go into the BIOS and load optimized defaults. I booted up the computer, and the bluescreens were gone. No random freezes either.

I sent the Corsair memory stick back since it was defective. I sold that computer system to my friend, and that system continues to run.

Now, this was just my issue, and your problem could be caused from something else. I'm hoping I can help you on this issue.

Thanks.

Thank you for your response, but I don't believe it can be a compatibility issue since its a laptop, and nothing was altered since I got it.

But I think I fixed it, the freeze was cause by a process KMSELDI.EXE stopping and causing the entire system to hang. I deleted it and so far so good.

Good, glad you got it figured out.