The symptoms you describe could be due to hardware or overheating problems caused by a failed processor fan, bad memory (RAM), failing power supply, underpowered power supply, CPU overheating, motherboard, video card, drivers, dirty hardware, etc. If the computer is overheating, it usually begins to restart on a more regular basis. If your not finding any malware then its sounds like the latter problem.When was the last time you cleaned the inside of your computer?
Dust restricts the airflow and prevents proper cooling. This in turn can cause overheating and faulty processor fans which can result in unexpected shutdowns, random restarts, booting problems, etc.
- Open your machine, check all the connections and make sure the fans are all operational.
- Check the heat sink on the processor to ensure it is not blocked with dust or debris.
- Remove the CPU's cooling unit and clean the fins on the heat sink that sits under the CPU with a can of compressed air.
- Inspect the thermal compound between the CPU and heatsink as it can break down over time so.
- Remove the cards and RAM modules, clean the contacts and reseat them.
- Feel the CPU heatsink when it powers down. It should be warm to very warm but not hot.
See "Cleaning the Interior of your PC
" and the "Illustrated How to Replace an AGP Video Card
" (use as a guide to clean & reseat).
Download and run Motherboard Monitor 5
. If Motherboard Monitor's seems to be reporting high temperatures for your CPU check to see what your max CPU temp is from here
There are suggestions for troubleshooting power supply, video card, CPU, RAM, MB and hard drive here
You can also use BurnInTest
to stress test the CPU, hard drives, RAM, CD-ROMs, CD burners, DVDs, sound cards, graphics, network connection, printers, video playback. This utility works on all Windows versions to include Vista (32-bit & 64-bit)
Another option is Microsoft's Online Crash Analysis
. The Windows Memory Diagnostic tests the RAM for errors with a comprehensive set of diagnostic memory tests. Also see Memtest86+
.Read the directions under Technical Info and allow the test to run for at least 3 full passes (or let it run overnight). Any errors indicate that there is likely a problem with your physical memory (RAM).
Finally, look for problem entries in Device Manager
and check if updates are available for your drivers