Just open a PSD file and PS appears. What exactly is your problem?
Ok, then a little bit more precise:
I am inside PremierePro CS 5.5 and there exists a function in the file menu (Link as above: File > New > Photoshop File...) that directly opens a photoshop document with the size, pixel aspect ratio and framerate of my current Premiere sequence. So i click on that and Premiere is supposed to open Photoshop. Instead it opens a program, that is called "Preview" (i'm working on a MAC, i forgot to mention that before, sorry). Now Preview is only good vor previews and not for editing images.
To put it in other words, my problem is, that Premiere should open Photoshop and generate a new file fitting to my sequence, but instead it opens Preview.
Of course, I could open a new PSD-File in Photoshop but then i would have to manually type in the size of the image and so on. And since there is a built-in feature in Premiere, i would like to use that instead of going the long way.
So basically i am searching for the place where i can "tell" Premiere which graphics program to open.
Ok, just to let you know, i figured out a way to solve this. It might not be the only way, but it works. Somehow, not all, but some .psd-files on my computer were not set to be opened with Photoshop as a default. Some others were, i don't know why. But i now changed the setting for ALL .psd-files to be opened with Photoshop and now as well the .psd-file vreated in premiere is directly opened with Photoshop.
Thanks for your reply anyway, best greetings!