Photoshop :: How To Change Starting Size On Screen...

When our photographer browses his folders with pictures and double clicks upon one of them (jpg-files always), his Photoshop (he uses CS3 and Windows NT) always opens up the file only shoving it as 16,3% size (or such, I can't remember the exact number)
As a result the picture hardly fills 1/4 or 1/8 of the available space in the Photoshop screen, and he always has to click the picture larger before being able to work in it.
He has recently got a new - and more powerful - computer, and he did not have the same problem when using the old computer, here his files always opened to the maximum possible size.