Returning to Window 7 after upgrading to Windows 10

I recently upgraded one of my Dell laptops to Windows 10. I guess I couldn't resist the 'free' offer. This particular laptop, though not that old, is obviously not conducive to Windows 10. I wanted to play solitaire and waited 15 minutes for the program to load. I never did get the game loaded. I want to return to Windows 7 but 10 doesn't make that easy. I no longer have the option to restart or shut down. When I turned the laptop off, it did not boot from the DVD, as I expected. I want to re-format the hard drive and just start over. Windows 10 doesn't seem to want me to do that either. That's problem number 1.

Problem number 2 is that I cannot find my product key for my Windows DVD. I know I had it and usually I am very good about writing it down and keeping it with the DVD, but this time it appears I did not. I have two laptops and the same software is installed on both. Can I find the product key somewhere on the other laptop?

Thanks for any help.

have you defrg.....

I figured out that Alt-F4 gives restart options, and if I keep hitting F8 and F2, I can get to the BIOS and boot options and change it to the DVD as the primary boot device. I am reformatting the drive now and will reinstall Windows 7 when that action is complete. Thanks for the help.