How can I tell what causes a freeze on my pc?

Recently I'm getting freezes from time to time, everything freezes up and not even the mouse cursor moves.
The pc never recovers from this even after 1 hour and eventually I have to turn it off and on again.

I checked the event log but it onyl contains information from the reboot and later, the actual freeze is not recorded.

I tried uninstalling some programs I know can cause things liek this (antivirus, media players, etc.) but since my pc has very bad wiring I am not sure if this will do any help.

Is there a way to tell what causes the freeze besides checking all of the hardware manually?

Thanks!

You can try these steps:
Troubleshoot Application Conflicts by Performing a Clean Startup

And you can test in the safe mode.

Do you use software that lets you see the temperature of the CPU, GPU, HDD/SSD....?

In addition work through these Troubleshooting Steps for Windows 7

but what happens is that I can't type anything. I can click on links from sites and do everything else, but I can't type in an email or on a form. I have to restart the computer and then it's fine. Anyone have any ideas what causes this?

i think it is hardware related n not program errors because the whole PC freezes n not a particular program. safe mode is always the first thing to use, see if it still freezes in safe mode. also, while in safe mode you can try using various maintenance tasks, i recommend using system tools to check hard drive for errors, then defragment. a quick solution also is going to advanced boot option (the one with safe mode etc) and choose 'use last good configuration that works'. quite a lot tips from others too above, for now, we'll see and wait for your next post.

Try changing the keyboard or using the on-screen keyboard: Type without using the keyboard (On-Screen Keyboard)

Report back results of the Troubleshooting Steps.

Thanks for the input, and I will try this.

Ok, after taking ages to get a backup pc, then sending in my pc to repair and getting it back yet later, I finally got my new pc and the problem is still there.
The bad wiring has been fixed (I meant that the cables get squeezed by the case when I close it but not so much that they would break), also the power cable for the hd has been replaced with one that has multiple SATA compatible plugs, the previous one actually had a single SATA plug and 2 IDE plugs (yes, even though I bought the PC 2 month ago and the mainboard does not support IDE anyway).

I also got a STOP Error 0x00000050 today, when I tried to restart after the pc had frozen up again.
Could this be because of a faulty HD?

I'll try to check the HD in safe mode, is there also a way to check RAM in safe mode?