Wsreset error "'ms-windows-store:PurgeCaches'"

nadia,

There are indeed compatibility issues between 8.1 and Avast, but these have been rectified by Avast. Check this artilcle to see how to update: http://www.getavast.net/solution-for-windows-8-1-and-avast-compatibility-issues

Can you also go right click the Start button and go to Programs and Features at the top.

In the menu which opens, click the link to "View installed updates" and then copy/paste the following two patches into the search field top right: KB2911106 | KB2919394

If KB2911106 doesn't appear in the list, download it from the following link because it fixed a large number of issues with the Windows Store: http://www.microsoft.com/en-us/download/details.aspx?id=41570

If you don't have KB2919394 you can download that from here: http://www.microsoft.com/en-us/download/details.aspx?id=41794

You have to reboot after installing each one.

Nothing wrong with your hard drive though.

I uninstalled and reinstalled Avast only a couple of weeks ago, so I know that's not the issue.

I've got both those updates already installed.  My problem started not when I upgraded to 8.1 from 8 but when I installed the 8.1 update.  The Microsoft Tech uninstalled it then reinstalled it but the damage had already been done.

Good news about my drive...one less thing to worry about.

nadia,

I think we have to figure out how you can take ownership of a file because we didn't resolve that problem earlier and it might provide the key to solving this equation. So try and do it according to this article: http://www.thewindowsclub.com/take-ownership-windows-8

If that doesn't work, there's another one which is a bit more advanced but is illustrated step-by-step using different options to achieve the same goal: http://www.eightforums.com/tutorials/2808-take-ownership-file-folder-drive-registry-key-windows-8-a.html

Before I do this, I found the registry backup that Microsoft Tech made before he messed about with it.  I've pasted it below, was thinking to restore this to the registry instead as my current one seems to have become a bit of a mess with things duplicated etc.  What do you think?

nadia,

I can't really say. The backup was made on April 9 which is one day later than when the 8.1 Update was released.

Can you recall whether you had installed KB2919355 already prior to the registry backup being made?

Also, did you pay for support because if you did, Microsoft should at least refund any fees you incurred since they were unable to fix the problem.