I want to Dual Boot my existing W7 pro with W10 pro as in Dual Boot Tutorial by Brink. I made W10 Installation USB removed fast boot & secure boot and installed W10. I have W7 (C drive) on a 500gb SSD and installed a new 500gb SSD for W10 (D drive) I installed W10 on the D drive no problem. Just as shown in the tutorial by Brink, How to Clean Install Windows 10. Everything worked fine except no Dual boot.

On reviewing my steps, I disconnected the C drive so that the W10 install would not install over my W7 pro. My plan was to run and evaluate W10 on a separate drive, adding Applications ie Quick Books, FedEx ship manager one at a time to be sure all worked well. If all OK then I would do another W10 upgrade over my W7.

1. But, I have no dual boot, I think maybe disconnecting the C Drive was wrong, I shot myself in the foot. Do I have to uninstall W10 and reinstall with my C Drive connected? If so, will W10 install on the C drive over W7, that would be a problem. Does the W10 install process allow me to select the installation location.

2. During the Install process, I was asked to enter my Product code I entered the code from my W7 Pro package but got an error message, product code was incorrect. I then checked the later box but I will have to solve this problem. The code I entered was from my W7 pro package?? what to do?

Thank You for any comments