There is no way to stop the adding of favorites that I know of. However, for the home page:
Do a search in the registry for a key named restrictions under the HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer key and delete it. Then reboot your machine and add the key back and lock your homepage as described below.
Or search for the word policies and check the values for the number 1. The number 1 USUALLY indicates a restriction is in effect. Post back with your findings.
To prevent further problems,
Correct your home page to the one you prefer, then immediately do the following:
Backup the registry and/or export the following keys:
go to Start>Run, type regedit. Navigate to:
HKEY_USERS\.DEFAULT\Software\Policies\Microsoft\Internet ExplorerRight-click on the Internet Explorer key, choose new>Key, name it Control Panel. Right-click on the Control Panel, chose new>DWORD value, name it Homepage. Right-click on Homepage, choose modify and type in the number 1.
This should lock your home page, so no other web site can change it.
Then navigate here and verify the homepage is correct:
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
look for the Start Page entry.
reghakr