Some frequent culprits:
1. Corrupted normal.dotm. Try renaming it.
2. Corrupted registry entries. Try deleting the data key in the registry.
It's here:
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Word\Data
*Standard disclaimer: editing the registry can cause problems if you mess
up, and can destabilize the rotation of the planet. Proceed at your own
risk.*
3. Misbehaving add-ins.
4. Incompatible printer driver.
The most frequent cause I've encountered in Word 2007 is #2 on this list.
So, that's where I would start. If you don't know how to edit the registry,
you might google the phrase "how to edit the registry".
