That really is s*cky.... BUT! Instead of saying how sorry I am for your situation, I'll list positive things!
1. No one got hurt. Not sure if you lock the look that's connected to the garage but those burglars could've tried getting inside.
2. Your furbutts weren't stolen!
3. As pain as it is to replace all the stuff that got stolen, at least it can be replaced.
Regarding your pc... is it a desktop? Could be the fan like you said or the RAM, power supply... If you have a old desktop you don't use, try switching out the parts. Have you tried running malware/spyware?