Okay. So I searched and searched for how to do this and figured it out. Depending on your computer speed, it may take a while, but isn't so bad IMO.
First, find where all the updates for windows are listed. Go to Control Panel ---> Programs. Then under Programs and Features, you'll see a link called "View Installed Updates". Under Microsoft Windows, scroll until you find KB2871389.
Uninstall it, and then accept the prompt to reboot your computer. The reboot is the part that some people are complaining takes a while. For me, it was about 5 minutes.
Now, login under your account (that has admin privileges) and then go to the corner until the floating menu comes up and choose settings. From settings choose change PC settings at the bottom. Then,
click on "windows update" at the bottom of the right hand side of your screen. Check for updates now and it will take a few minutes, but they will find one (KB2871389). There
is a message telling you that it will download automatically in a few days, but ignore that, click on the link for one important update, and choose install now (or some such thing). Then reboot, which again, took me about 5 minutes but I saw some complain
that it was 45 minutes for them.
Now you are all set. Log in on an admin account, go to the store, choose the 8.1 update, and now, no admin problems. Eureka!!