I agree with alphanumeric's post, that you basically have 2 choices: uninstall or system restore. Sometimes a program/app corrupts during the downloading process. You can uninstall it and then reinstall it to see if you still have the same problems after the second installation. If you decide to uninstall/reinstall, be sure that you have removed all of the program's remnants before you reinstall it. I usually do a manual Advanced Search, in which I search my whole system (rather than just the indexed locations) for any files or folders related to that program, and then delete any files or folders that are found.
If you continue to have the same problems after the reinstall, then check to see what restore points you have on your system. If you have something very recent (so you won't lose too much if you restore from that point), then you can do a System Restore.