G'Day
Are you trying to delete it or uninstall it?
If you are trying to delete it - you cant. Open Control Panel then select Add or Remove programs, tick/check the show updates box and then scroll down - it will be near the bottom and then click on it to try to uninstall it.
Another option you can try is to download WiMP 11 and install it again, it may not have installed properly the first time and failed to create the uninstall file. After installing again try to uninstall it.
As Sarah Loiuse states you can also try System Restore to go back to the time before you installed it, but be warned you will also lose all the programs (but not any files you created with the programs) and updates you have installed since then - you will have to reinstall everything you lost during the restore.
Geoff