So you're having computer trouble, but you don't quite know what the issue is. Maybe the computer spontaneously reboots, or maybe programs aren't loading. Perhaps the computer has stopped booting all together. If you have a little computer know-how, then you can use the Ultimate Boot CD to fix the issue.
Got to http://www.ultimatebootcd.com/
Download the files to make the .ISO from the download section. You can ether use the .exe file to extract the actual .ISO image file, or download the .ISO directly.
Take the .ISO file and use any CD burning software to make a boot CD from the file
Put the CD into the drive of the computer with the issue you are trying to troubleshoot.
Go into the BIOS and set the computer to boot from the CD-ROM drive first.
Boot off of the CD-ROM. From there, you can use the UBCD's tool set to test and troubleshoot the system board, the hard drive, the file system, and even scan for viruses and other male-ware.
Make sure you have a lot of down time to run any of the tests off of the UBCD. Many of them can take hours on a slower PC.
Be careful using the partition and wiping tools under the “hard drive tools” menu. You can easily lose all of your data on the drive if you misuse these tools. If any of these tools and names seem like “Greek” to you, then you should probably invest in a professional repair service to look at your computer.