In control panel->add/remove programs, only a handful of programs are listed
where there should be dozens. Also, the few that are listed no longer have
the option to either change or remove them. It just shows the size and when
they were last used.

I don't understand... just a few days ago it was fine. All programs were
represented and had the option to remove.

Note: this is not a problem of white space between programs; those listed
are from A to Z and there is no scroll bar.
I also cannot change the information for each program in regedit under
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Uninstall\<Program
Name>
because only 1 program is listed there. None of the dozens missing from the
add/remove window are listed in this folder.
I also have updated virus and spyware protection.

Please help. I have hit dead ends on this problem for days.