Computer Getting Whiny

Fan noises on my tower computer have reached annoying levels, so I pulled the side panel and spent some time dusting with compressed air and a Shop Vac. The whiny sound has been cut at least in half, but it’s still noticeable. It may be time to try a new CPU fan soon, as I think that’s the one that’s most irritating.

It wouldn’t be too bad if it were a steady sound, but the fan responds to load, so it’s constantly rising and falling in pitch.