Windows update: Install error - 0x80073701

Hi,
no matter what I do, I still have the same error. I have already contacted Parallels support. Unfortunately none of their solutions worked. I've also searched Internet and tried things like: SFC and DISM scan, running Windows Update Troubleshooter, clearing the software distribution folder. None of them worked.
I've just thought maybe I could just somehow completely reinstall the whole Windows system. Can I do that with the same license key?
Since I only use it for Excel I'm not afraid of losing any files or documents.
I would be very kind if anyone could help.

 

I am having the same problem. Frustrating beyond belief.