I presently have three partitions; one is win. 98(10gig) and the the other xp(10gig). While one more partition that I use as storage(of 20gig). My question is, if I decide to format/remove win. 98 and install unix...would it be possible to do so without disrupting the Winxp....and also, as a question is it possible to have on one system; win. 98, winxp and unix??? all functional...just out of curiosity, how much space does unix take up and how efficient is it(I have heard quite!)?? Thanks.

i say try it and see that linux does all that windows can do but more ifficiantly, but that you have to learn to understand

As to how "efficient" UNIX is, it totally depends on your preception. If "efficiency" for you includes "does it run ALL my current Windows applications without much fiddling", then it's probably not very efficient.

As regards the system requirements: That depende on what flavour and version of UNIX you choose. For NetBSD e.g., requirements can be VERY low: That is not to say that UNIX was only for old computers. It you throw top of the line hardware at it, chances are you'll get unrivalled performance out of it.

Without having any actual hands on experience as regards your scenario, here's what I would do in your case:

1. Back up all partitions, just for good measure.
2. Convert or reformat the 20 GB partition to FAT32 (if applicable).
3. Shrink that partition to 10 GB. This 10 GB FAT32 partition will be your jointly accessible storage volume, i.e. all your operating systems will be able to access it. (There are tools out there that can do all of these things, but I don't know them offhand. Google for them or ask specific questions in these forums.)
4. Create a new partition on the remaining 10 GB and format it ext2 or something else (whatever filesystem the flavour of UNIX you're installing supports best). It is, I hear, possible to install UNIX OSes on existing FAT32 partitions, but as a matter of personal opinion I believe it's useful to strictly stick to a "default" environment when learning a new OS -- you can always move on to more non-default, advanced features later.
You should thus end up with the following:
- your 10GB Win98 partition
- your 10GB XP partition
- the aforesaid 10GB FAT32 "common storage" partition.
- a 10 GB partition with some UNIX OS installed on

From the Linux camp comes the LILO boot manager (boot loader) that you can install, allowing you to easily select any of your OSes at startup.

I would not do away with any of my current OSes until you're fully at home in and happy with your UNIX OS.