I don't know if this is possible or not but I wanted to ask if you can help me:

1.- Booting from cd/dvd
2.- After booting from it, then: Loading from hard drive or pendrive some configurations (network, programs, etc).
3.- When I shutdown the computer only what I want will be saved in this hard drive or pen drive configuration (only browser updates and add-ons updates)

I know I could use a pen drive with persistence, but I don't want my knoppix to be changed in any way when I am using it (to avoid virus, malware or who knows what). That's why I need to boot with cd/dvd and load some minimal configurations.

Ideas?
Thanks a lot.