I created sevaral seamless patterns and defined them as patterns in photoshop but I didn't save them as .pat files.
I lost Photoshop preference data and I can't access those unsaved patterns. Where can I find those unsaved patterns?
If the preferences got corrupted and were restored they are gone, unless you used them in a file (as Pattern Layer, Pattern Overlay, …). In that case you could recreate them from there.
If you have some back-up system you could try to locate the »Patterns.psp« that still held the patterns (Users\[user name]\AppData\Roaming\Adobe\Adobe Photoshop [version]\Adobe Photoshop [version] Settings).
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.
AdChoices