I have a nice Dell Precision desktop replacement laptop, and a while back, I noticed that it had a cool software driver feature. When I enabled or disabled NUMLOCK, I’d get a visual notification on the screen that this had happened.

Unfortunately, I eventually found that this feature interacted poorly with some remote desktop and VM software, causing the notification to flicker on and off distractingly. Occasionally this happened to me when I was trying to run a presentation on my laptop. Nasty.

Today I spent the effort to find out how to fix the problem. It turns out that this clever little feature is an undocumented feature of the Dell bluetooth driver’s tray application. You can eliminate it by killing the tray icon application BTTRAY.EXE. Disabling the icon in the app’s settings does not do the trick, you must kill the app. There also is no configurable setting in the app to disable the NUMLOCK visual notification.

Luckily, there is a registry setting that can disable the feature while allowing you to use your bluetooth device fully.

[HKEY_LOCAL_MACHINESOFTWAREWidcommBTConfigGeneral] 
“KeyIndication”=dword:00000000 

After changing this key, restarting your computer or 

C:Program FilesWIDCOMMBluetooth SoftwareBTTray.exe

will disable the popups.

If this does not work for you, look into ‘quickset’, as others have reported that it also can cause this issue.