old Win98 system: how much space? Can I dual boot?

I have read many different threads with little direct help, so I give up: I'll just post my questions and hopefully someone will have pity on me.

I have an older computer with an AMDK6-400, 2.1 gig HD. Every 8-9 months Win 98 goes unstable, and I am tired of re-installing. I have played around with the 3.4 Knoppix live CD on the machine-- it is slow, but fully functional. I want to just do an HD install of some form of Linux. Ideally, I would like to keep the Win98 stuff, but I am willing to do a low-level format and just have Knoppix/Linux as the only OS. My daugter uses this computer to surf, chat using AIM, and word processing for school assignments. We want it stable and running effeciently.

1) So, do I have enough HD space, or am I just dreaming? (I am probably under some limitations on HD size since the machine is so old, I think)
2) Would I be better off installing Debian right off the bat, or is it just as good (maybe a little easier) to do a Knoppix HD install?
3) can you point me to any guides someone has already compiled?

TIA,
tnrocketman

You don't have enough space for a hd-install of Knoppix, but you could get something like Damn Small Linux. I'm not sure how realistic dual-booting a 1GB drive is...I'm sure it's possible, but it's hard for me to imagine. Your daughter could do all of those things with linux of course. :D

Actually, I lied about the HD size. I just double checked: it is 2.1G (edited above post to reflect this).

I didn't see that you said how much memory you have, but if it's at least 128MB that system should be a bit of a slowpoke but not horribly so.

As remarked, your hard drive is too small for a HD install of Knoppix--but it isn't really so small you need a mini-distribution. If you like Debian and complete hardware detection you might look at the new Xandros Open Circulation Edition. It's free if you download with Bittorrent (which means it's available for about $3.00 from Edmunds), but something like $10.00 to download by FTP. And it will take up just over 1GB on the hard drive, including swap. Or there's Morphix.

Otherwise, Slackware would be ideal on this kind of system. And if you don't want to manually configure everything (the norm for Slack) you can borrow some of the scripts used in Slax (a live-CD distro based on Slack).

If you have 700 Meg free, you could do a 'poormans install' Knoppix, essentially it copies the CD to the HD & runs it from there. Install by booting Knoppix 'lang=us tohd=hda1'. You could then set up a 'persistent home' & save your Knoppix configurations to the HD so everything doesn't always start up defaults.
If you have the space, it would be a good idea to partition the HD so the operating systems are on one partition & the data is on another, especially if you are having problems with unstable systems. That way, if your O/S crashes, you don't lose your data. So you might be looking at 1.5 G for O/S depending how big the win 98 install is, (I recall they could be pared down to about 700 Meg or so without too much problem) (ie 700M for win98 + 700 M for Knoppix) which would leave 600 for data. Put both O/S systems on hda1.
You do not have enough space to do a Knoppix HD install (takes 2.3G minimum) but you could make a remastered smaller Knoppix...or use Morphix which is a 'modular' Knoppix derivative. I would try the poormans install first, it's easiest.
Installing Knoppix is WAY easier than installing Debian, in fact a lot of users (myself included) use Knoppix primarily as a 'Debian installer' rather then a run from CD system.