How to tell if my PC is dying

Solution
Computer's don't "die" as such. Components can fail, but that is usually just a single component from the total (and even then, actually highly unusual). Most likely you have problems with your Windows install and/or drivers that don't work (e.g. Creative's audio drivers are pretty much guaranteed to give system instability, but there are other notorious drivers out there for other 3rd party peripherals). I'd start by reformatting your boot drive, and installing Win 10 (or 7 if you must) and see if your instability persists.
The easiest way to eliminate software as being the issue is to format your PC.
Then see if it runs fine on a clean install.

If it still freezes from a fresh install, then you have hardware issues.
You could also do this as a small test
1. Press Start + R
2. Type: msconfig
3. Go to tab called: startup
4. Disable everything.

See if it still freezes up, then you know one of the startup applications was causing it.

As far as the hardware goes, if you have two or more stick of ram remove all but one, and put in a different one every time to test them.

Try removing your graphics card, (if you have on-board graphics).

If you can eliminate hardware like this you'll be able to pin-point the problem.
"not graphics card, not ram, could be Motherboard or power supply."

This will also prevent you from buying an entire new pc. :)
 
Computer's don't "die" as such. Components can fail, but that is usually just a single component from the total (and even then, actually highly unusual). Most likely you have problems with your Windows install and/or drivers that don't work (e.g. Creative's audio drivers are pretty much guaranteed to give system instability, but there are other notorious drivers out there for other 3rd party peripherals). I'd start by reformatting your boot drive, and installing Win 10 (or 7 if you must) and see if your instability persists.
 
Solution