Quote Originally Posted by OP
Is integrated onboard graphics problematic in Knoppix? Sometimes Knoppix v5.1.1 keeps hanging with the message: Probing/loading AGP modules... root!tty:/#

sometimes the boot process goes smoothly. Would a PCIe card cure the problem?

Thank you.
Most integrated graphics are Intel video, which is well supported in Linux. Maybe you can use Google to search for information about you model of computer and Linux, or about your video chipset and linux.

You can always try a separate video card, but make sure that it is supported in Linux before purchasing that card.