Sometimes a computer can get pretty caked up with dirt. This can cause overheating/shutdown issues.
- I have an electric vac/blower I use that works great. Instead of compressed air. It is much cheaper, blows harder & longer, & there is no "vapor" that mists onto the hardware. You will need to lock the blades with a qtip or other safe device before doing this, but I would blow the case out good. Do it outside, because if you do it inside, you will be breathing computer dust for days. Make sure you lock the case fan blades, graphic card fan blade (if you have any other graphics card installed), power supply fan blade, & CPU fan blade. Be sure you clean all of the areas that have fans, since they will need to be clean to operate safely.
- Try disconnecting anything you do not use. This includes if you have DSL (but still have a dialup modem inside), old sound cards, whatever. This is to eliminate all possibility that the connected hardware is/has got fried. I know 1 pc that kept rebooting because of a fried 56K modem that got really hot to the touch.
- Try disconnecting the memory sticks if you have multiple ones, & reseat (after you have blown the PC out) them. Alternately, try using only 1 stick at a time to be sure that it isn't failing memory. Be sure you first ground out static electricity by touching a bare metal part of the case while the computer is off so you don't fry the memory.
- Remove the battery & reset the motherboard to defaults (in case of overclocking/bad settings/timings). Usually, 30 seconds to 1 min is enough. Boot up, accept they have changed, then pop the battery back in. Alternatively, try disabling the shadowing options(s) for the CPU in the Bios.
- Inspect your capacitors. If they have rounded tops (instead of flat), you have something wrong. These will cause data errors & blue screens until replaced.
- Try something like Ubuntu. I tested React OS, Windows ME/2000/XP/Vista/7 on a laptop with motherboard problems. All failed. Ubuntu seems to have some sort of fault tolerance handling that isn't present in Windows. I thought about testing later to see if I ran Windows 7 inside a virtual machine (or XP!) while in Ubuntu to see if that worked...
- Also, if you have a PC with a good powersupply (or can visit a place that sells them), they are usually around $35 or slightly more. Not too bad. Failing power supplies can definitely cause above stated problem. Recommended you get a $45 APC unit with battery backup from Walmart to plug all your sensitive devices into (stereo/computer/monitor), being careful to not overload it beyond rated watts.
If any of this helps, let us know. If it doesn't, let us know.
Peace!
* Last resort -> Check for updated bios (usually from your PC manufacturer website, IE, Compaq/HP/Gateway, etc) & flash your computer. Use this only if you know what your doing & plug your computer into a UPS with battery backup so if power is unstable during flash, you won't end up with a brick for a PC.