Background: Sometimes Photoshop can exhibit odd/erratic/weird behaviour. This behaviour can sometimes be overcome by removing the Photoshop Preference file. The procedures outlined below are the most common methods of removing the preferences file.
Q: I am experiencing weird behaviour in Photoshop. - How do I delete / reset my preferences?
Photoshop Versions 6x and later:
A: Hold down Alt, Ctrl, and Shift keys (Mac: Command, Option, Shift) while starting Photoshop. A dialog box will appear asking if you wish to delete the preferences file.
A2: You can also simply search your hard drive for a *.psp file and delete it. It will be called something along the lines of "Adobe Photoshop X Prefs.psp".
Under Win 2k/XP the preference file will be found at:
%windir%\Documents and Settings\~username\Application Data\Adobe\Photoshop\[version #]\Adobe Photoshop [version #] Settings
[NOTE: You need to set Window's Explorer Options to "View Hidden Files and Folders" to display the Preference file]