Try using Revo Uninstaller. Even if it can't uninstall the application normally, it will force it to uninstall by wiping out all traces of its presence from the system.
After that, try running AdwCleaner to make sure that there are no leftover rogue registry keys or toolbars in your system.
If after these operations, you still have issues and the software is there, use Combofix and wait for a full computer scan.
Note: During the scanning process, the Internet or any other 3rd party applications running will be closed automatically.