Mt office assistant won't work how do I activate it?

You'll have to install it.

Put in your Office CD and
Click on START > Control Panel > Add/Remove Programs
Click on Microsoft Office and click MODIFY
Go through the Shared Office options and find the entries for the Office Assistant
Make sure you set it to Run from my computer
Complete the wizard and let it add the missing files

If this doesn't work, you may just need to run the Detect and Repair option from the Help Menu inside Word.

Try those things and report back here your results.