How to change these things in cs3 extended

cant seem to find where to change these things! this is what i need them to be.

Banner: 468 x 49
Leaderboard: 728 x 79
Square: 250 x 239
Small Square: 200 x 189
Large Rectangle: 336 x 269
Medium Rectangle: 300 x 239
Skyscraper: 120 x 578
Wide Skyscraper: 160 x 578

thanks in advance!

Eric,

You can either just create and save new presets which will appear in the dropdown menu of the "File > New..." dialog, where you currently choose from Default Photoshop Size, Photo, Web, etc., or you can modify the "Default New Doc Sizes.txt file" in [root installation path]\Adobe\Adobe Photoshop CS3\Required. Note that while you can open the file in Notepad or some basic text editor, one such as Wordpad will format the file in a more readable way; just be sure you still save it after editing in a TXT format. Oh, and heed the notes in the header.

Regards,

Daryl

ps: these are not squares... Square: 250 x 239 Small Square: 200 x 189