Sometime I have Developer tool stuck that can’t open window but is added to the task bar.
this worked for me:
1. Close all of your IE Windows
2. Delete the registry entry: HKCU\Software\Microsoft\Internet Explorer\IEDevTools\WindowPos
(optionally, type the following at a command prompt)
reg delete "hkcu\software\microsoft\internet explorer\iedevtools" /v windowpos
3. Open IE again.
4. Press F12 to open the dev tools