If you are facing this error then DO NOT try to force uninstall Bluestacks using Revo or iOrbit uninstaller.
Step 1: Restart your PC
Step 2: Close Bluestacks from Notification Panel by Right Click and select Close.
Step 3: Open Task Manager, go to Processes tab and if you see any of the Bluestacks processes like 'HD-Agent' or 'HD-Frontend', then right click that process and click 'End Process Tree'.
Step 4: Uninstall 'Bluestacks App Player' first and 'Bluestacks Notification Panel' next. If it still doesn't works then try uninstalling Notification panel first and App Player next.
Step 5: Delete any Bluestacks named folder from: C:\ProgramData\
Step 5: Run CCleaner to clean up any residual files or Registry entries.
Do not forget to say thanks if this works for you.