It's best to get the old GnPlayer / Bluestacks off your PC prior to installing a new bot and MEmu. First, try the regular windows uninstall of your emulator.
The below should only be used if the regular uninstall fails.
1. Quit BlueStacks
2. Download the Bluestacks Uninstall Cleaner
3. Click “Yes” if asked for permissions and troubleshooter should start fixing the issue.
4. Once it removes all the traces of BlueStacks completely from your system, the below message should be visible on your screen.
5. Click OK to complete the process
6. If Bluestacks failed to install again, try further cleaning it using the video tutorial below