We have already covered about the replace as you type option in Word 2007. The same feature is also available in Word 2010 under the Proofing options. One of the reader this blog had the following question regarding replace as you type feature.
Problem I am encountering is I am creating autocorrects for frequently used words and phrases, but as soon as I close document or shut down, and restart, all of it has disappeared
If you come across similar problem then you can check the ACL file for the missing entries. ACL file contains the pre-existing autocorrect entries as well as new entries. And this file can be located under the following path
C:\Users\<username>\AppData\Roaming\Microsoft\Office. Where <username> is your windows username.
You can quickly analyse this file by adding a new autocorrect entry and then save the document. Now navigate to the above ACL path and look for any ACL file has been modified recently i.e date near to the current time.