MOTHERBOARD

This may or may not be your problem, but I had the same problem and fixed it. if you're using a Dell desktop like I am, check the boot lights: 1,2,3,4. If you're not then i'm not sure if you have those boot lights, but if you do, then go for it.

For a guide to these lights go here. http://support.dell.com/support/edocs/systems/dim5150/en/sm/tshoot1.htm#wp1120147

For me it was lights 3 and 4, I removed one of my two 512 MB memory modules (you can search pictures of everything if you don't know what it is on google) and the problem was fixed. I believe that you can make up for the lost module by increasing your pagefile or better yet buying a new one.

If you don't have the manual for the motherboard, go to the manufacturer's website under support and try to find what you can. The specifications would indicate the type of BIOS software is also important to keep in mind. At leased th Mobo isn't dead yet. Remember the series of beeps, because it indicates specifically what the problem is, or which hardware may be malfunctioning. And a few last things to keep in mind. Make sure the hardware is installed properly(eg. reseating the memory,cable connections, etc.). Also minimize the amount of hardware or devices you have connected, just have enough to make it run, like one memory module, one cd-rom and so on. Hope you fix it.