A:AnswerYou should download the Windows 10 media creation tool and boot from a USB. Then do a clean install of the Operating system. If you used an M.2 SSD you will have to change the boot order.
A:AnswerThank you for reaching out. The PSU is a standard, Small form factor 12v power supply, an ATX would not fit. As for the GPU, you would need a half-width compatible model and it would fit.