Hello. I know that it I 2014 but if anyone is still having this problem you can do something very simple. I had the same problem and all you have to do is change it over to your local account.
You can do this by taking the following steps:
- Go to the settings bar and click Settings.
- Then go to Change PC Settings that is located at the bottom of the bar.
- Then click Users.
- Then click Switch to Local User.
- This will then prompt you to create a local user, which is yourself, which will give you the privileges you need to download Windows 8.1 with no addition problems.
If this continues to say you need permission, then I suggest you look at your account settings in the control panel and make sure that you are the only person on the account.
Hope this helps.
This worked for me
I switch to a local account and then switched back by signing to my Microsoft account and Windows started the download from the Store.
It was really simple yet - It should not happen since I always sign in my computer with my Microsoft account and passport.
The problem I was seeing was that windows 8.1 upgrade was visible in the store but when I tried to install it would give me an error saying that I needed to be log in a administrative account.
Problem solve ! (for me anyways).
p.s. Microsoft should hire more software engineer and manager from Google to builf a better quality product :-)