All Access Denied

If no one can help I completely understand. Recently installed Win10 over 8.1. Went to redo ownership, got interupted, accidentlly deleted all accounts on security tab for C:, with only my account left, and before I could check "full access", I applied the settings. Now I have no full control or modify. Also when I go to advanced I can not change "Owner: TrustedInstaller".
I am now completely locked out. Can not even run CmdPrpt as admin. Very close to doing a hammer format on a new touchscreen laptop. Please Help!! Thank you.

Do you have a Restore Point from before the change? If so you may be able to slide by booting to Safe Mode and running that Restore Point.

The other option short of a complete install may be to boot a rescue disc/usb and restore the registry from backup. There is a step by step procedure for this but after 1/2 hour of search I cannot find it. You could also try automatic repair if you made the bootable rescue utilities usb. It is easier if you have the Windows install media. But I bet your system came preloaded?

Also if you haven't already, it may be worthwhile to post your question on Windows 10 Forums
since you have W10

Thanks for the reply, and I'll give the Win10 forums a look. Sorry for any hassle. I am locked out of all "command" functions. No reset, no image restore, no restore points, will not let me create, nor use, back-up discs. Also, preloaded 8.1, upgraded to 10, then everything went wonkie.

It is no hassle. It is just that the regulars on the Win 10 forum will have more experience getting around problems such as yours. They may know how to back out of the W10 update without losing files and/or suggest what to do as precautions before tweaking on the next attempt.