Being new to this Lounge, my wording may differ from Lounge standards, but bear with me please. I recently faced the following problem:

The ctrl+end shortcut suddenly stopped functioning. I posted a question through http://answers.microsoft.com/ and received the following answer:

Click the Office button.
Click Word Options.
Click Customize.
Click Customize ... at the bottom of the dialogue next to Keyboard shortcuts.
Click in the Press new shortcut key box.
Press Ctrl+End
If you do not see Ctrl+End appear in the box, you probably have a mechanical problem with your keyboard.
If Ctrl+End does appear in the box, it should currenctly be assigned to EndOfDocument. If it is assigned to something else, select that and click Remove.
To assign Ctrl+End to EndOfDocument again:
Select All Commands in the list of Categories on the left.
Select EndOfDocument in the list of commands on the right.
Click Assign.
Then close the dialogues.

I hope Lounge users will find this useful.