Q: When I click on Photo Shop 7 Icon it loads the program, then dissapeard. I've tried re-installing PS. How shall I use PS again?
A: Hold down Ctrl-Alt-Shift while starting up Photoshop. You should get a dialog asking if you want to reset Preferences. Click Yes. It should work but you will need to remake any Preference settings in Edit>Preferences.
or Delete Adobe Photoshop 7.0 Prefs.psp on x:\Documents and Settings\User\Application Data\Adobe\Photoshop\7.0\Adobe Photoshop 7.0 Settings