Scenario: Consider present infrastructure got AD, DNS, DHCP and RIS. DHCP and RIS installed in old server. You bought new server that required to move RIS and DHCP. This is how, you can accomplish your objective. Consider ServerA will be decommissioned as RIS and ServerB will be commissioned as RIS.
Step1 Backup DHCP
Step2 Copy all RIS images from ServerA from separate storage \\ServerA\REMINST\Setup\English\Images
you can use XCOPY Source destination /Y /X /O /E /H /K /C from command prompt.
Step3 Stop DHCP and RIS services in ServerA
Step4 Install new server i.e. ServerB and Patch up
Step5 install DHCP in ServerB, restore DHCP from backup and start DHCP service
Step6 install RIS from add/remove windows component and run RIS setup
Step 7 delete *.pnf files from \\ServerB\REMINST\Setup\Images folder
Step 8 Copy all previous image using XCOPY command to new server i.e. \\ServerB\REMINST\Setup\Images folder
Step9 restart RIS service or reboot new RIS server
You are ready to go.