If you are using Windows Vista and Adobe Photoshop CS2, you may have noticed that you are constantly asked if you would like to register the program every time you launch it. In order to work around this, simply right click on the Adobe Photoshop CS2 shortcut in the Start menu and click "Run as administrator", and then provide consent when User Account Control asks you.
You will be asked to register, click on "Do not register" and then close Adobe Photoshop CS2. Re-launch it normally (without running it as Administrator) and it should open without nagging you to register.