During/after disk 3, it should ask to select the type of software load - either Standard or Service - select Standard.
It will then ask for the Teach Pendant Text disk (3HAB2356-1 for RW2.1) and after it starts loading, it then asks to select language, IRB type, mounting.
It then asks for the IRB disk (3HAB2340-1 for RW2.1 IRB6400 M94A) and load the appropriate files for the IRB type previously selected.
After loading the IRB info, it will then ask if there are any option disks. I suggest answering NO until you get the motion part working.