Try Smart Defrag. This is a really good deep-defragmentation/optimization tool, and it's free. As far as disk cleanup, you might want to google that up.
I wouldn't recommend going that far with editing Windows settings unless you know what you are doing. There are some hidden tools that are really meant for those who know what they are doing, and how to do it. I would recommend being really careful with such tools.
Well, about getting your system back, you probably should look to see if the .exe files for these programs are available from Microsoft or some other site. You might be able to get them back.
It might be easier if you have System Restore turned on. If you do, run it (and if you aren't absolutely sure what I'm talking about, ask me before you run it This is not the same thing as restoring from a previous image of the C:\ drive. ). If you aren't don't have it turned on, you might have to stick with other options.
Last edited by blakesterville on 2010-11-10, 18:08; edited 1 time in total