I scanned with sisoftsandra and I got this message... " One of the mainboard fans has failed or is spinning too slowly. This should appear only if the mainboard has a temperature-monitoring sensor installed and the fans have tachometers. If the fan is speed controlled, this may be normal. Fix: If the fan is not speed controller, power down the system immediately. Open the case and check that all the fans are working and check whether components are unusually hot inside. Make sure the components have good all-round ventilation." How can I know for sure something is wrong?