Why does my PC makes a grinding sound on boot up? It is worse in cold weather or when the PC has not been on for a week. It stops after a minute or so.
Chris Myers
Grinding noises are always bad news, but the most common cause is a failing fan, and that's what it sounds like. Your PC may have several fans to cool the processor, a fast graphics card, the case and the power supply (PSU).
You will probably need to open the case and listen to find out which fan it is. Replacements are available but if the culprit is the PSU fan, you may need to replace the whole PSU. If the noise is coming from the hard drive, make sure your work is backed up because it may be starting to fail.
It may be possible to free up a fan with a tiny drop of oil (but don't use WD-40). Dan's Data has a page on fan maintenance that will help. A UK company offers a lubricant called FanLube, but I have no idea if this makes any difference.
