Hi!
Does this problem occur specifically with the letter T? If you hold down SHIFT and press another letter, like A, does it work?
Have you tried using the virtual keyboard? Press Windows + R > Type osk > click the SHIFT key and then T.
If it only happens with the T key, perhaps some background app is using the SHIFT + T shortcut. Start in safe mode and see if the problem persists.
- Press the CTRL + R shortcut > Type ''msconfig'' (without quotes) > Click on the ''System Boot'' tab > Check the ''Safe Boot'' option > Click ''OK''.
- Restart the computer.
To exit Safe Mode, access msconfig again (Step 01) > In “General”, check the “Normal Startup” option > Apply > Restart the PC.