If you have as you say 3.08 installed and also 3.09 as a portable (inside a folder)then we could try a couple of things.
If you can, can you move the portable folder to a usb stick/flash drive (everyone calls them something different!)so it's out of the way for now, you can always put it back later.
Then can you look inside the 3.08 program file folder and see if uninst.exe is listed there.
If you are able to open 3.08 make sure check for updates is unticked
Then can you download 3.08 again from here on the right where it says 'old versions' and save it to your desktop or downloads folder.
http://www.filehippo.com/download_ccleaner
Then double click on it to install it. It should overwrite the 3.08 version that is there and hopefully repair it so you can uninstall it.