I have Win XP SP2 Gigabyte MOBO AMD Sempron. The system is about 5 years old. I had changed the bios to alarm at certain temp to avoid overheating. After 4 yrs alarm started. I TOOK off the SIDE casing to allow more air flow and that stopped it. I then gave the computer to a relative who left the casing on and after 4 or so months of continued beeping, the computer would startup, beep then shutdown. I openned the case and used a vaccuum cleaner to get the dust out. I removed the case fan and cleaned it. Then I removed the fan off the heatsink and there was an enormous amount of dust caked in the heatsink. I cleaned that out and now the computer starts and runs for about 1 minute. It gave me just enough time to pull up the task manager, click on processes TAB and sort the CPU column. The entire column is 00 including the System Idle Processes. My guess is a burned out processor. Any IDEAS?Yes... I'd say that AMD is cooked.

AMD's burn up and crack if they overheat. The older ones like your was not engineered with Thermal Throttling like the Intel CPU's. If the system is important to get back up and running you can get a AMD Sempron Replacement on ebay really cheap Semprons are a worthless processor for most, they are the Celeron of the AMD series like the Duron. The processor to have is the Athlon, and you can probably also install the Athon in place of the Sempron and get much better performance. I have an AMD Athlon XP 2800+ ( 2.08Ghz), 1GB Ram, and 8X-AGP GeForce 6200 video and the trick to keeping it running is to keep the CPU cooling fan clean of obstructing dust blankets. This system is good for gaming, but not as good as my 2.8Ghz P4 with HT CPU, 1.5GB DDR2 Ram, and PCIe Geforce GT8500 Videocard.Thanks.