Hi.
Office hasn't been working properly on my computer since I bought Office Home and Student 2016 (not Office 365) in December 2017, but I will start with the latest:
Office said from the beginning that it encountered a problem and needed to close, so I've been trying to solve that. I also called Microsoft a few times, and they tried to help me, although it didn't lead anywhere.
Today I ran though the list here:
https://support.office.com/en-us/article/i-get-a-stopped-working-error-when-i-start-office-2016-or-2013-applications-on-my-pc-52bd7985-4e99-4a35-84c8-2d9b8301a2fa?ui=en-US&rs=en-US&ad=US
So, I came to "remove and re-install Office" since the previous options didn't solve the issue. It seemed like disabling add-ins manually helped a bit, but still didn't fix the issue completely.
So, when I first tried to re-install Office, it went almost all the way through and then said it encountered a problem and gave me the error code 30015-11 (-1073610698). My Computer is in Danish, but it means "Something went wrong. We encountered a problem.
Go online for more help" and then error code:

When I now try to re-install Office after removing it completely I get the error code 30068-39 (2), and I can't install at all. I've tried restarting several times with no luck:

I then tried this method:
https://support.office.com/en-us/article/Error-code-30068-when-installing-Office-963ca3e4-217a-4c16-9c02-ff946548357b
When I run services.msc and go to Office Click and Run, I get the following window, which says "description couldn't be read. Error code: 2"

So, I'm stuck here. Any help would be greatly appreciated.
Now a bit of background:
I bought Office from a non-Microsoft website, as I assumed it was okay (didn't cross my mind to only buy directly from Microsoft, as I figured it would be just like going into a computer shop), and they later told me that they get their product keys from
Microsoft's partner distributor.
So, a while after installing, Office started crashing. It was mostly Word I used, but occasionally I would also use Excel, which would also crash with the same error message, which says "sorry, but Word has encountered an error, which causes it to not work
properly. Word has to close down. Should we repair the error now?" and then the options to repair, help or close. This is the error message I've had through the entire period, and pressing "repair now" has never changed anything.

When I spoke to Microsoft on the phone the first time they said that my activation key had been used too many times so it had been deactivated - as in they believed the company (or someone else) had sold the key again after selling it to me. The company
that sold me the key has given me a new key twice, and I had Microsoft check them and they said that they were okay (at least the last one, I remember). The last time they gave me a key, they forwarded me the e-mail with the key from the distributor.
The company in the end, when I explained a bit more, said that it was a computer issue, not an issue with the key, which makes some sense to me, although I'm not sure.
When I had Microsoft on the phone, they also tried removing Office and re-installing it, and the same error message appeared, as above, after Office was almost completely installed.
So far nothing has been able to solve the issue. In May my computer crashed and had to be reset after the Window update 1803 that many people had problems with. So I also had to re-install Office. The reset "helped" for certain other small issues with my
computer, but didn't change anything for Office.
Again, any help would be greatly appreciated as I'm completely stuck here.