For you win clients, use the registry.
Copy this text and save to a file with a .reg extension (for 2000 and xp)
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main]
"Start Page"="http://www.thebennetthome.com"
Modify it to suite your needs, place it in a share that your users have access to, then in your login script call it using regedit /s filename.reg.
If you have win9x or I believe the top line needs to be changed from a 5 to a 4. You can easily test this by opening regedit and exporting something. The top line will show you the syntax
Also, if you have a mix of win9x and 2000/xp you will have to check for %OS% and then point the clients to the proper file for regedit to import.
Here is a quick example:
@echo off
if "%OS%" =="Windows" goto windows
if "%OS%" =="Windows_NT" goto NT
goto regular
:windows
regedit /s win9xhomepage.reg
goto regular
:NT
regedit /s homepage.reg
:regular
rem this is the rest of your login script
My win2k and xp machines %OS% = Windows_NT, I don't have any win9x machines to check, but you should be able to go to a command prompt and type set and see what the OS variable is set to.
Hopefully, this give you a decent start.
Good Luck,
JB