Sorry that this is long and not that well worded
I really messed up. So from the beginning. I bought a pc from one of my friends on Friday. (Specs: cpu: Intel i7 4790, gpu: nvidia geforce gtx 970, motherboard: gigabyte z97 hd3, and Windows 10 home, originally pre-installed with Windows 7 Pro)
Everything worked great and today I just download gta 5 and when I loaded I noticed the performance was low even when every setting low. So I contacted him how much fps he would get when he played and he said around 120. So I looked around and saw that it was using a gpu on the motherboard or something. It was the Intel hd graphics 4600. So I searched on how to change from the hd graphics 4600 to Gtx 970, and in some forum someone said to disable it. So I did and when I did the monitor said no signal(that is the problem).
So I panicked and searched how to enable again so I read that you should take out the cmos battery out of the motherboard for 10 min and I did. Nothing. I tried it again and nothing. So I saw that I should try to reset the cmos with a jumper. But there was not cap that you would use so I used a screwdriver and touched both of the pins for 10 seconds. Then nothing. Then this is where I smart but at the wrong time. I had the dvi connected to the Intel graphic card instead of nvidia Gtx 970. So I thought finally connected it to the Gtx 970 and started up my computer.
So I finally saw that it was starting up then bios popped up I followed everything and when I pressed exit it showed Windows starting up but instead Windows 10 it was Windows 7. So I continued to try to install Windows 7 and it gave me two choices. To upgrade or custom install. I didn't want to do custom install since it would delete every file so I clicked upgrade but it would show a message saying "The computer started using the windows installation media. Remove the installation media and restart your computer so that Windows starts normally. Then, insert the installation media and restart the upgrade. [Do not select | Custom [advanced]| to perform an upgrade." It then looped to the beginning of the installation and would keep looping.
So I tried to get a media installation media for Windows 10 on my laptop opened it pressed create installation media for other PC and followed it. Moved all files to a usb connected the usb to the PC and tried to boot it with the usb. I followed the steps when it told me that I needed a product key which I didn't have and neither did my friend. So I tried to download the media installation media for Windows 7 but before I was able to download it asked the the product key. So I looked on the case of the PC (it was pre built from cyberpowerpc) and I typed the product key that showed. It cancled and said that it was a product key for a pre-installed Windows so I was unable to use it. Sorry for making this long by the way. I'm out of ideas. Hopefully this can be fixed.