Location is greyed out, i cannot remove internet explorer 11 addon after virus removal

I understand. There have been threads about difficulties doing a reset, too. You could be braver with a system image on hand to recover what you've got should the reset go bad. I've got a Seagate Slim 2 TB external hard drive with several images on it, Win 8.1 & Win 10. Of course, there are threads about system images that won't restore, too. But that makes two things that need go wrong for total disaster. Three things, if you've taken the Win 10 ISO download which can do a fresh install...

https://www.microsoft.com/en-us/software-download/windows10

Download Windows 10

Also, you might have a factory recovery image of Win 8 somewhere on your hard drive. Mine on partition 7 would get me back to Win 8.1...

...In fact, it already did it once. About a week after I bought this Dell Inspiron 3542, I locked myself out by inadvertently changing my password. It wasn't fun - because clicked icons & buttons often gave no feedback & took time to get to the next step - but the Dell procedure did work.

So, I clicked to turn location off in Action Center. Cortana changed its icon from...  to . It displayed a message that it would help to turn it back on, & it had diminished usefulness - but still worked. I could still get it to find an app by typing its name. I could still ask Cortana, even for the weather. It would BING for it. But I couldn't talk to it, & it wouldn't grab the weather & stuff & put it in its display, like...

(1) You don't see that stuff in Cortana, do you?

(2) So, what are the missing files in SFC.log?

(3) Did you run the DISM?

Cortana was installed automatically when I upgraded to Windows 10... It was working fine... When I turned off Location, Cortana would not work and instruct to turn Location On first... But after the virus... Cortana worked even with the Location in the Off mode... In the Location tab, I tried to click CHANGE for the Location for this device is off... nothing happens.

I know something is not right since on my Sony Vaio, I could click CHANGE for the Location for this device is off... and the Location button in Notification is not greyed out. And on the Sony Vaio, Cortana will not also work if Location is turned off.

This was Windows 8 when I bought it.. I upgraded it to Windows 10 two (2) months ago.... I'm hesitant about the reset coz when a colleague did it, she encountered a lot of errors... and until now was not able to get Windows 10 again with her Windows 8...

The picture you posted long ago indicates location is stuck off...

...Do you ever see that circle-within-a-circle icon pop in & out of the taskbar? I see it occassionally, at start up especially. It pops in/out of the taskbar just to the right of the "Show hidden icons" icon (^). Cortana may be using a different process. Or, you did have location working at the time Cortana was installed. (IIRC, Cortana wouldn't install otherwise.) But now you don't. Anyway, you should be able to turn it on/off.