first backup any file you edit in /etc
sconed backup any file you edit in /etc
be veary careful with /etc/initab ,/etc groups , /etc/passwd and /etc/liloconf
IF you have disk the space to spair make an extra 500meg partion for back up copys of work you don't want to lose this is just in case you can't figure how to fix your system and need to reinstall later on you can use this space for a rescue system to fix things that can't be fixed from a running system like a damaged file system
Don't be afrade to reinstall when you are first learning I know that one of the boasts of linux users is we never need to reinstall but hay your just learning and reinstalling is a fast way to fix what ever gets hosed
good luck

to the forum admens ---------------------------------------------------------------------------------------------

I thought I was posting this in the linux newibe forum not here would you please move it