My uncle left this HP Stream 7 tablets at our house, saying we could have it if we could fix it. Whenever it's turned on, it goes to this BLUE screen that reads:

Recovery
Your PC\Device needs to be repaired
The application or operating system couldn't be loaded because a required file is missing or contains errors
File : \$Windows.BT\NewOS\WINDOWS\system32\winload.efi
Error Code: 0xc000000f
You'll need to use the recovery tools on your installation media. If you don't have any installation media (like a disc or USB deivce), contact your administrator or PC manufacturer.



Press the Windows key to use a different operating system

but, nothing happens when you PUSH the windows BUTTON on the bottom. I've tried Googling the problem already, but I can't seem to find anyone who's having a similar problem. I don't know anything about it aside from what kind of tablet it is. This might be what you have.
http://support.hp.com/us-en/product/HP-Stream-Tablets/7439994/model/7482041/drivers
This document MAY help some:
http://h10032.www1.hp.com/ctg/Manual/c04495010.pdf
And go to the HP forum.
http://h30434.www3.hp.com/t5/Windows/HP-Stream-7-Windows-10-doesn-t-boot-I-can-t-recovery-8-1/td-p/4968314

That is the best I can do for you.