1. CPU area should be clean and ventilated
2. Check Wires/Cables, UPS.
3. Disc Cleanup
4. HDD Checking
5. RAM Cleaning
6. Antivirus Checking 
7. Recycle Bin, Cache Memory & Temp files Cleaning etc. 
8. Removing Dust from SMPS, PCB Board using Blower. 
9. Inform to Respective person to arrange their Desktop. ( for C-Drive load issues)
10. Heating Problem
11. Check for Windows Updates when Required. 