You don't delete programs though regedit, what are you doing exactly? Or do you mean though Add/Remove Programs?
You can try running though a Repair option in Windows Setup, that should restore things to normal and not remove your files. Although that may not fix anything in your case as it has no way of knowing what registry entries were added after the initial setup. Try running the setup for the programs again, can do a Ra-install or a Repair to get things back so you can uninstall it again.