What is the white box for? It appeared when you enabled Tablet PC?
Look also at what is cued when you click the up arrow to is' right. Those items which you want to keep should be moved to the taskbar and the others should be dealt with.
I would achieve a clean boot to make sure no program is freeloading on your startup and possibly causing problems:
Troubleshooting Steps for Windows 7 - Windows 7 Forums