I think the PSU might be under power/quality, A clean version of windows is recommended, since you did some migrations that aren't considered "good health" for a OS.
Things you can do:
- Install Windows, clean.
- Look (physical) for blown capacitor on the motherboard
- Download HWinfo (for the rails voltaje) and OCCT (for CPU/VRAM/PSU testing),
- Memtest86(+) for memory testing (only two I trust),
- Uninstall AVG and go for avira, bit defender o windows defender,
- Update BIOS
- Update Drivers (Snappy Driver Installer, driver easy, etc)
- Clean the OS with Cleanmgr+ (if didn't format)