Update- I also had an issue regarding my cpu being incredibly high for no apparent reason so I clean installed windows again and that problem has disappeared, can't speak for the reboots yet though.
[Edit] Nope, just rebooted twice, once due to TaskScheduler (?)
[Another edit] I'm not sure what happened with Task Scheduler but I ended up opening my computer and found a couple of loose connections to the Motherboard (including the 4 pin one next to 24 pin), so I'm assuming it's that for now. Anyway if I don't write here again, assume it worked.