Add remove programs was new and never enforced by Microsoft. It's also just a listing of programs that voluntarily added such to the list. Fast forward to your issue and the list can be easily deleted by Malware, an accident or a registry cleaner.
No one has written a program to re-populate this list.
-> This is why third party uninstallers are popular.
Windows XP media center 2005 . When i go add remove alot of the programs are not listed. Why? I want to uninstall a lot of them but are not there. Where are they?