I have a feeling that some stuff is still left from a prebious uninstall. Please do the following :
download Ccleaner here
update it. Under options advanced you will see something like " create a backup of the register ? " tick that.
Start Ccleaner klick on problems and tick everything with the register and start analyzing. After it is finished you will get a default question whether you want to make a backup. As a default it will be stored in " My Documents " . If smething goes terribly wrong you can, by double klicking , reinstall this backup.