This could be caused by some spyware you got infected with. Do the online check with housecall.antivirus.com, and download and run adaware and spybot.
The homepage is defined in the registry (HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\Start Page) and can be changed with regedit, maybe.
If you've got Windows 98 (and no profiles!) you could boot into MS-DOS and do a scanreg /restore to yesterday's version of it. That would restore the ActiveX security settings also. Have you tried to restore them to what they were with Option>Tools>Security?
In Windows XP a system restore might be possible, but it depends on how long ago you made a restore point if that is feasible.
Hope this helps.
Kees
my homepage is set to the MSN gaming zone, but i want to change it. I went to internet options, but NONE of the buttons to change it are filled in, they are grayed out, so i cant change my home page. Plus i try to join a game there and it says ActiveX controls are disallowing it to display correctly. was not doing this yesterday. uninstalled Zone files and tried reinstalling but noting happened. am stuck with nothing. how do i fix the homepage?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic