- - - - - - - - - - - - - - - - - - - - - - -
                         W I N D O W S   X P
               - - - - - - - - - - - - - - - - - - - - - - -
               REMOVE ADD PROGRAMS FROM MICROSOFT OPTION IN
               ADD/REMOVE PROGRAMS

You can use the group policy editor in XP Professional:
- click start, run, gpedit.msc, click ok
- go to USER CONFIGURATION\Administrative Templates\Control Panel\
  Add/Remove Programs
- Double-click "Hide the add programs from microsoft option and
  click disabled, click ok

You can use the registry for XP Home Edition:
- open the registry
- go to HKEY_CURRENT_USER\Software\Microsoft\Wundiws\CurrentVersion\
  Policies\Uninstall
- create new dword value NoAddFromInternet
- give it the value of 1