The PC arrived in a not turning on state. After resetting the motherboard and isolating components we found the power supply is shorting and refusing to turn on. We installed a tester PSU and it turned on fine.

Removed all dust and bugs inside the PC and then installed a new PSU. The system was running Windows 7.

Backed all personal files to a Seagate 2TB HDD and then upgraded to Windows 10. Then set up automatic backup and updated the drivers and other applications to ensure smooth transition and 100% compatibility with Windows 10.

System is running smoothly and quietly.