"So i want to have Windows 10 on my new PC and my new PC will be for gaming it will run I7 and GTX980ti" 1. If you buy a new PC, we can assume it is delivered with Windows 10 (Home?) preinstalled. 2. If you build your PC, install W10, skip the key during install and activate with a KMS tool.
If you have Windows 10 that was upgraded from Windows 7 and you wanted to do a clean install to "get rid of all the crap", Select start, settings, update and security, Recovery and select "Reset this PC" Select the option to "keep nothing" and it will ask you if you have other drives connected to the PC (Just C: drive or all drives) I did this upgrading from Windows 7 (a clean install of Windows 7 Ultimate) and as soon as the upgrade was done, I was able to do this and nothing on the "C:" drive was available, it was completely wiped. It also kept everything on my other drives/partitions. As I understand it, it's just like formatting and starting over and you don't have to deal with the activation crap, if you were activated before, your activated now. Also, after 511, you can use a Windows 7 KEY to activate Windows 10...