Uninstall the "Send to Bluetooth Add-In"

First find the location of the Add In dll:

to find the btsendto_office.dll go to File/Options/Add-In select the Send to add in and observe the path at the bottom of the screen

Close all office applications and unregister the Add In with:

regsvr32 /u "C:\Program Files\ThinkPad\Bluetooth Software\btsendto_office.dll"

If you want re-register the Add In with

regsvr32 "C:\Program Files\ThinkPad\Bluetooth Software\btsendto_office.dll"