[Roy Dennis]

Have you tried un-installing, then when you re-install check the box that states do you want to remove all previous settings (or words to that effect) if that doesn't work either put in a support ticket or try this:
un-install Hoster, then use system restore to return your computer to the date before you installed Hoster on it.
Then do all the Windows updates again as these will have reset, checking as well those instructions described in the previous error message you received.
Now if you have access to it (check your account page) download and install 5.06 version or an earlier version you were using before this latest update, try that if that works OK then download and install 5.07, that will install 2 icons on your desktop a Hosterprior which will be your 5.06 and the ordinary Hoster icon that will be 5.07 both which should work just by clicking their icons.