Windows 10: I can't get out of an account that isn't mine

My computer files need me to log into my Microsoft account but every time I try, it has the email of my brother's friend and I can't leave that account to input my own email. I tried looking up ways to fix this but I haven't found anything, there's nothing in the setting I've found to fix this problem.

:)

 

Printer isn´t working after latest update.

After the latest update from Windows, my Canon Pixma ip6600 printer isnt working. In Device Manager it shows up as working properly but when I go to print it isn´t listed as an option in any programs. Troubleshoot suggests it´s a USB 2 printer on a USB
3 port and that that´s the problem but that cant be since it worked fine before the update. I´ve tried to uninstall and plug it back in but that doesn´t work either.

 

Cortana isn´t working

When I hit enter, it did something, but there´s still no Cortana, even after restart. So I tried it again, but now it says that it failed, because it´s already installed and it´s working in PC. So it should work, but Cortana still isn´t here.

 

UNABLE TO ACTIVATE WINDOWS AND NUM LOCK ISN"T WORKING

UNABLE TO ACTIVATE WINDOWS IN SYSTEM AS WELL AS NUM LOCK ISN"T WORKING