Lovely conundrum.

After an hour of frustration and a giggle at the appropriately titled Word 2007 crashes aren’t a bug, they’re a feature, it occurred to me that I went through this exact issue some time last year. A quick hunt through my del.icio.us bookmarks revealed the answer in the form of the Microsoft Knowledge Base’s article about crashes in Word 2007, Word 2003 and Word 2002.

The issue is with a corrupted key in the registry. The steps to fix this problem are:

1. Exit all Office programs.
2. Open the Registry Editor by selecting Start, Run, type regedit, and then select OK.
3. Locate the following registry subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Word\Data
Back up the registry key (select the Data folder, and then select File then Export. Call it whatever you want and save it to an easily accessible spot like your desktop).
4. Delete the Data subkey (select Data, then select Delete from the Edit menu).
5. Exit Registry Editor.
6. Start Word. Ta da!

Hopefully this will save you some hours of frustration!