This message was posted on behalf of Intel Corporation
Thank you for contacting our support community. We understand your situation regarding the Intel® SSD 600p Series.
We would like to inform you that the reason why you can not install Windows* 7 in the drive is that the OS does not have inbox NVMe* drivers as Windows(R) 10 does.
In order to install the OS, we recommend you to perform a secure erase and follow the next installation guide.
The installation process starts in section 3.1 but you may want to read the whole document.
Also, you may also want to engage your computer manufacturer since you are reporting BIOS errors.