I would recommend going into your Blink config file folder, copy and save the machine.xml file (settings and preferences you have made in Blink) and then completely uninstall Blink 3.0. Reboot your system and clean up any temporary files left over on your system from Blink. It may also help to clean out your windows Temp folder too afterwards. After you have done try to install the 3.1 Beta version of Blink again. If you do not mind making all the personal changes and preferences in Blink again go ahead and do so, otherwise what you can do is shut down Blink, go back into Blink's config folder and replace the machine.xml file with the one you saved if you wish.