I've tried holding down the Ctrl, Alt and Shift keys in every way I can imagine and still can't reset to defaults. What am I doing wrong or is there another way?
#1
You are probably not quick enough. You need to press all three keys together immediately after clicking on the PS icon. The good news is you can delete the prefs file manually. In CS2 it is Adobe Photoshop CS2 Prefs.psp and is located at:
Documents and Settings\UserName\Application Data\Adobe\Photoshop\9.0\Adobe Photoshop CS2 Settings
#2