Windows

If you want to set per-user scripts this is still done in the properties for the user account in active directory.
If you want to set a script in group policy, you have options to define startup and shutdown scrips under computer configuration, or logon/logoff scripts under user configuration. If you are wanting to map drives for all users you will probably want to put this in the login script in group policy. If the mappings are different for different groups of users then assign the relvant script on a per-user basis through their account properties.

Hope this helps :-)

In addition to Ed's usual excellent comment, you may want to hotlink this link for Windows 2003 GPO info:

http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/management/gp/default.mspx

Ed really nailed it but just some extra stuff:

If you wanted mappings based on group membership then there
is a resource kit utility called "ifmember". The URL is long so you
may need to copy and paste:

http://www.microsoft.com/resources/documentation/
WindowsServ/2003/all/techref/en-us/Default.asp?url=/
Resources/Documentation/windowsserv/2003/all/techref/en-
us/ifmember_remarks.asp

Other than that I prefer do as much as possible with Group
Policy. It will allow everything you ask in one way or another.

razz