Is there an AutoComplete feature in Word 2007?

"AutoComplete has been disable in Word 2007. The large number of Building Blocks that exist would cause AutoComplete to trigger essentially all the time.

You can force completion after typing the first four characters by pressing <F3>. This will work with any Building Block, not just AutoText. However, it will only work if there are no other entries that begin with the same four entries.

You can also use Quick Parts. To use a quick part, type its name and press <F3>. To create Quick Part:

Select the text you would like to save as a Quick Part. This can include text, pictures or any other objects that Office recognizes. There is no size limit. You can actually use an entire document as a Quick Part, such as a cover letter or form template.
Use Alt+F3 to open the Create New Building Block dialog box.
Give your Quick Part a name. Your name can be as short or as long as you like, but short, of course is better.
Type a description and optionally, select a Category for your Quick Part.
Save.
From the Options menu, select how you want the text to appear every time you press F3."