Please answer my questions, if you wan't me to help you. You don't answer anything.
What do you mean it won't let you? How do you try to uninstall?
If you uninstall an application, then the .dll should also be removed, unless you have moved the dll from the install path? Do you manually move dlls from install paths, so you have multiple installs?
If you have removed a program so it can't be seen in Windows program manager, then you can remove remaining files manually.