Ms office 2003

[mss]

I insert AutoText entry, and it disappeared. Word

[sittas87]

if the problem persist all the time,reinstall office

[slurpee55]

By "it disappeared" do you mean that it isn't available when you open another document? Either you are not saving it to Normal.dot (the template that holds such things for all documents - but you can save it just to the one document) - did you get a notice that said something like "Do you want to save changes to Normal.dot?" and not click okay?
The other possibility - and this is common as well - is that Normal.dot is corrupted. In that case, with Word closed entirely, search for Normal.dot (it may be hidden) and, once you find it, rename it to something like oldnormal.dot.
The next time you open Word it will create a new Normal.dot - but only with the default settings, not with any changes you may have made.