Before you do that, give this a try:
Do a search on the drive which contains your MS Office directory for a file called "Normal.dot". This file is very often corrupted, and when it is such, it causes issues similar to yours. The good news is that it automatically regenerates itself when it is deleted. When you find it, rename it to "Normal.old". And then restart word.
If that doesn't work, go to start -- run -- type "word.exe /s"
That should start MS Word in safe mode. From there, if you're running 2002 or above, you can go to Help -- Detect and Repair. It can only do so much if you don't have the disk, but give it a try anyway.
Hope this helps.