Since this was a beta and we were encouraged not to overwrite our good install, I endeavored to comply. I created a new account.
My main account is administrator level, my next account (beta) was user level on Win 7.
Installing the beta as a user caused complaints in the logs that it could not write into a given directory (The logs are in my other thread "Crash immediatly after install 4ab1").
I eventually had to install and uninstall several times.
Uninstalling does not remove everything. This is a flaw in windows software in general. When I click uninstall I want everything removed. I don't want any data - any registry keys - anything at all to be left behind. I've had to go repeated to appdata and remove the remnants of one version or another in order to make sure that the following install would go smoothly.