Awhile back, I ran into problem when I was updating my Bluestacks and uninstalling didn't help. After researching for a bit, it seemed like Bluestacks sometimes left behind files and those files will screw up your new installation. It has been awhile, but if I remember right, the three places you need to check is the program file, appdata in your user profile, and registry. If you find a bluestacks folder/entry there, you will probably have to remove them before reinstalling.