I assembled a computer for myself about 11 months ago. It was my first build ever, but I seem to have done well-enough. However, I sporadically run into a problem where the audio hangs, all computer functions immediately cease, and I'm then forced to either restart or power-down the computer.
In short, it is very much like a blue screen of death, except that my monitor loses the visual display (it goes into idle mode, and then powers down after a few seconds).
Since not having a blue screen to view, this ongoing problem has been hard to diagnose, as these crashes are completely random, sometimes happening within 10 minutes of boot up, sometimes happening after hours of running fine, sometimes after hours of low-CPU work (such as MS Word).
What exactly happens when a computer gets a "blue screen of death"? ; Could there be an actual 'blue screen of death' occuring that, because of my monitor, I just can't view?
A BSOD happens when the windows kernel encounters an error that it cannot or does not know how to handle, this is usually software related but sometimes can occur when hardware malfunction causing the software to lock or crash.
I think what you are experiencing is not so much an OS or software issue, but more a direct hardware issue. The first thing I would check if I was you would be your RAM, being that it is a random lock up and not after a set amount of time, I am guessing part of your RAM is bad. First I would check to see that all of your RAM is properly seated on your motherboard, and clipped in (I accidentally didn't have one clipped in and experienced your same problem). Then I would download a live boot linux CD (I would go with Ubuntu) and the CD usually has a RAM checker right off the boot screen (the newest cds you need to push a button on the keyboard to get to the menu). This will check your RAM for consistence and that it isnt causing errors. If this checks out I would then guess either your CPU is over heating and to download something like speedfan http://filehippo.com/download_speedfan/ or CPUZ http://filehippo.com/download_cpuz/ and watch your CPU temp very carefully. If it is overheating then remove your CPU fan and clean off the thermal paste and apply a new coat. Make sure that it is seated firmly. If THAT isnt the case I would then fully boot into the linux live CD and (or view the speedfan SMART date from your HD, but I've found speedfan to be wrong in this area before) and view the system disk stats. If your HD is failing in an odd way it would cause your CPU to instantly lock up. IF all of these arn't your case I would check to see if removing any add-on cards fixes your problem (graphics, audio, usb, etc) as if one of these are bad, the whole system would lock without any warning, such as BSOD.. but this is most unlikely (hence being last)
Oh one thing I forgot, power supply! I would rank the power supply right after RAM checks out... your power supply could be randomly bad or sending poor voltage to your system. If you cheaped out when you bought the power supply or bought one with not enough watts for what your system need then THAT right there is your problem. They also do go bad randomely so dont think your safe even if you spent a lot of money on it. Your best bet for this would be to either buy a power supply tester (and get one with good ratings because cheap testers are not worth investing in)... or buy a new power supply. If you plan on building more computers I would buy both right off the bat, if not then just buy the power supply. As chances are your power supply is bad, and even if it isn't, well it is one of the most likely things to go bad in the future and is always good to have a backup. newegg.com is usually where i go to get that stuff... and always check the ratings