I think it really does depend on the application. Try doing a Google search
for the applications that you don't have information about reinstallation or
repair procedures. Type in something like How to uninstall ...name of
application. Or How to repair...name of application. I know that for
example, I have read a lot of NG discussions on the best way to reinstall
Xp, some think a clean install, rather than repair or In Place Upgrade is
the way to go. I have found a lot of useful information by doing a Google
search. I recently had to repair my Norton Av, and albeit, the directions
were somewhat lengthy, the recommendation was to remove all aspects of
Norton, then, reinstall.
Sorry I couldn't be of more help. Good luck, though.