qnx 6.2.1 installation problem

please can someone help me with qnx installation problem, I have got a old machine 400mHz cpu, and 256mb ram. the CD disk is fine as I can install QNX into another PC.

I can boot from the CD, and start installation by copying qnx files and start QNX, the problem is the next stage of installation after I login as root.
the system prompts me CD repository, and I can choose packages, but I can not install, the install button is in grey colour.

thank you for any help!