Reinstall, and from now on set update to notify. Do one or two at a time and you will not have a problem.
Iknow you said that you do not want to reinstall, but thats what I would do.
Others are going to come along and give you suggestions on how to fix the problem. Some will work others will not. You can be reinstalled in 30 minutes. When you are up and working make an image of the OS and put it away, for problems just like this. You can use the copy and be up and ready in a few minutes, programs and all.