As a last resort, you can manually delete the program's folder and use a registry cleaner like CCleaner to remove leftover entries.
If the file is located in C:\Windows or a temporary folder, or if it consumes high CPU while you aren't uninstalling anything, it may be a virus. How to Fix "File Not Found" Errors skachat fail unins000 exe
It is an executable that runs the "uninstaller routine" for a specific program. As a last resort, you can manually delete