Hello, so I am working on an Emachine that starts, I can get to the BIOS, the hard drive I already replaced and the power supply so I try to boot the comp with Windows XP, Windows Vista, and Windows 7 and all come back with the same problem, it gets to the startup screen, sometimes it will get further than others but it never finishes and then the comp shuts off, I can leave the comp on for as long as I want in the BIOS and it does not shut off, it has two sticks of RAM but it is dual channel and it seems to detect both and I ran Hirens Boot CD and it detected no memory or hard drive problems, could the problem be a faulty motherboard??? And why, or could it be the RAM or still the CPU? I am not sure which part to replace next!
Try running MemTest86+ 4.1. Download it from here . You'll want the .zip file that has the .iso (disc image). Open the compressed file using winzip, winrar, etc. Next burn the image to a cd. If you're not using Windows 7 (embedded image writer), use programs like power iso, ultra iso, etc.
Once the .iso is burned to cd, properly, insert the disc (if it popped out after burning) into any optical drive and then restart your computer. Memtest will automatically run. Allow the testing to run for at least 8-10 passes (about 8 hours).
Note that if the testing finds errors at any point, the tests will stop automatically. The errors found will display in red.