you might try this....
http://www.microsoft.com/downloads/details.aspx?familyid=cda7f9fc-fe32-4826-a646-d64314178888&displaylang=en
Hi,
I'm testing RIS with Windows XP SP2 and a Windows 2000 RIS server. I've updated Windows 2000 to support RIPrep from XP.
The original image was created using a CD based RIS installation. I then installed the drivers for the computer and did some profile setups and copied it to the Default User profile. I then ran RIPrep but it didn't go smoothly. When copying files to the server some files in %systemroot%\system32 couldn't copy due to a sharing violation probably because the system is in use. Now when I try to do a RIS install of that image the client gets an error message stating that a temporary unattended answer file cannot be created. How do I fix this?
you might try this....
http://www.microsoft.com/downloads/details.aspx?familyid=cda7f9fc-fe32-4826-a646-d64314178888&displaylang=en
Windows 2000 Ris server not support windows xp client.
From Windows 2003 sp1 Ris is only Supporting Windows xp.
Windows 2003 sp2 WDS (Windows Deployment Services) server Support win2k,winxp,win2k3,vista.
So You can upgrade your Ris server to Windows 2k3 sp1.
http://technet2.microsoft.com/WindowsVista/en/library/9e197135-6711-4c20-bfad-fc80fc2151301033.mspx?mfr=true
For Ris win2k3 sp1 Installation Step by step
http://www.alanphipps.com/WindowsAdmin-Server-RIS.html