This will work for all Office '07 Programs (PowerPoint, Excel etc.) but Word has been used as an example
1) Open your program, and click the office button (top left)
->
Click the 'Word Options' button (obviously differs between programs)
This dialogue box should pop up:
Be sure to check the circled box.
Press ok
Now the Developer tab should be there along with all the others:
If not - try these steps again!The Developer tab itself looks like this:
with options mainly for visual basic and macros, but a couple of other settings to be found too - for example, another method of showing the file path in the header/footer (as explained here)
If you have any further issues, please do not hesitate to post here, and somebody will reply to you in no time =]
