...i don't want to lose all my plugins for the program. What do i do?
First thing, make certain you actually have to reinstall. For example, what happens if you just turn off the computer, go have a cup of coffee, then turn it back on, launch AE and open a project file? Or if you mess with your multiprocessing settings, and double-check the drivers for your third-party card?
Write down all the pulgins you installed. Gather all the applicable installers. Follow Mylenium's advice on the Cleaner Tool when uninstalling, then bite the bullet and reinstall the plugins. It's a Right Royal Pain, but you'll have to do it. Sorry, no shortcuts here.