Hangs are as difficult to diagnose as BSOD's because there can be so many causes. Actually they can be more difficult to diagnose because at least the BSOD does a dump with information about what caused it.
Look for clues in the event viewer. Go to control panel (classic view), administrative tools, event viewer. Look at various events (double-click to see the details) and see if any of them seem to correlate with your hangs (or seem repetitive). Look at both the application and system log. Also look in device manager. Any device malfunctioning?

One thing you'll often get asked is: is your PC properly cooled? I think overheated components can fail and cause hangs too. I'm not sure how to monitor temperature, but I think there are menus in the BIOS to check that. (I also don't know how high is too high).
Check all your connectors - particularly on the hard drive (both power and data). Also check all your cards are properly seated (memory too). If a component is loose and suddenly gets disconnected, even for a fraction of a second, you can get a hang (why I'm not sure - I think it's current getting recircuited or something).
Less obvious, check for any bulging capacitors. (http://en.wikipedia.org/wiki/Capacitor_plague has some pics - some kind of dramatic, but just make sure they don't bulge on top - it doesn't have to leak to be bad).

If all else fails, it's possible some component got shorted or is dead (or semi-dead). You'll have to go the long way and find out which one. Unplug and disconnect everything you can to leave a minimally working PC (just leave hard drive, graphics card, unplug network, sound, modem, DVD, etc.). Then boot it and see if you still get your hangs. If not, then just plug one item at the time and restart see if it hangs. Do it until you find your faulty component. When you find the "faulty" component, try plugging it into a different slot or bay (sometimes it's the connector that's at fault, and the component itself, and that simple test can differentiate the two). Sometimes you won't be able to find the cause that way (for example if it's something faulty on the motherboard).
Not sure what else to suggest.

P.S: Before you open your case, be sure to ground yourself. Static shocks can destroy components in the case and are probably the biggest hazard to electronic components.

 

Okay, thanks for the reply, now looking at the event viewer... i'm not really sure what i'm looking for i really don't know what's normal to find in their. In system it looks like i have lots of DCOM and Service Control errors, what ever that means. But it looks like more Service control errors. Also i don't know if it's relevant but they show up together all the time there's seldom a Service Control error not right next to a DCOM error. These errors don't seem to corelate with my hangs though. For security success audit every ten minutes or so but about 10 times a second, probably normal. *shrug* Applications there's no errors and just a bunch of mumbo jumbo.

But i'm thinking the hard drive is the problem. Do you think if i did install windows on another hard drive, and just used this one as storage do you think that would stop the problem or would it persist because im still using this one as storage? Also is there somewhere i can acquire a windows disc to install from.. my computer doesnt haev a floppy drive or nething. but i do have a legit copy of windows only .. no disc ..

Anyways i'll try what you suggested and see if that changes anything, thanks for your help.

 

What makes you think it's the hard drive? Yes it could be the hard drive, but not in the way you describe it. Installing Windows on another hard drive and having a separate drive for data shouldn't affect operation at all (if both are functioning well that is).
The kind of hard drive errors that cause hangs (other than actual failure) are like this. It's usually power-related. Sometimes I'll get a hang, just like that, everything frozen, mouse not moving. I put my hand on the hard drive to feel whether it's spinning or not (I have an open case BTW), and it's not moving or vibrating or anything (meaning there's no power to the drive). Usually if I wiggle the power cable a little bit, it'll spin up again (meaning it was a bad contact or it came loose at some point). Obviously the hang won't go away and I'll have to reboot, but that's how I diagnosed that. That can happen if the connector doesn't hook up well, but there's another scenario. If your power supply is underpowered, sometimes components will shut off all on their own just like that. I had that at one point (lots of times hard drive will shut off - then when it spins up you hear a click - but too late, the OS already hung), and it went away when I bought a new power supply. I don't know much about power supplies, and I'm not sure about how much power you need (it obviously depends on what components you have too), but you can ask around the forum about that.

As for a copy of Windows if you don't have the disc. Remember to back up all your important data if you plan to reformat (or even if you're just doing a repair install). Just call Microsoft at the number in this thread. Be sure to read both number 2 and number 3. If you need to retrieve your product key because you don't have it written down, get produkey (google it).

As for the event viewer errors, they're not very informative unless you read what's in the actual error report (double-click the actual event). Copy and paste if necessary.