what’s the easiest way to backup win-xp?

I have pcs with both win-xp Home, and win-xp Pro installed.

What’s the easiest way to backup for each?

Issues:
1. on the hp pc with xp-home, the cd choice won’t come up as an option when selecting a back-up location.

2. on the dell pc with xp-pro, there’s not enough drive space or memory for the back-up to take a snapshot of, or copy & store the temp files while the back-up is being prepared.

thanks-all