I was having a few problems so decided to uninstall. What a mistake.
On reinstalling all I get now is a logo inviting me to uninstall.
There are otehr instructions to do with a manual uninstall using registry etc but how a dimwit like me supposed to know how to do all that?

Your report makes no sense whatsoever. get_iplayer never prompts you to uninstall, nor does the installer. The only time you are prompted to uninstall is, unsurprisingly, when you run the uninstaller. But you can't get the uninstaller unless you successfully install get_iplayer in the first place. Start over, provide a detailed and cogent account of the steps you followed, and post some screen shots so we can see what is actually happening on your machine.