i want to totaly break from microsoft...i am running xp with 256mb ram. i have ordered the ubuntu cd, and 2 586mb ram chips that will put me close to the 1.5g max ram on the sony x750 im on...Question. i would think down loading another os would totaly wipe all my factory settings and xp os, which is what i want..if it won't then i want to take a magnet to my hard disk before i insert the ubuntu..if the later is the case, are there any other components i need to be aware of that the magnet shouldn't come in contact with. im not stupid but i am totally ignorant about downloading another operating system...i will of course research all i can before doing anything..any help pointing me in the right direction would be most appreciated..i should be getting the chips and disks in about 4 days...would also like to know if i should even start with ubuntu or start with an older version, i mean the dvd was only 8 bucks, id give linux a hundred dollars before i give microsoft another penny!!! thanks for any help, im ignorant but i am willing to learn.

During the installation of whatever distro you choose, you'll have the option to remove all partitions and filesystems on the drive, which you can use to wipe out Windows if you so choose.

As long as you don't use some really strong industrial magnets (the types used on junk yards to lift cars) that will do exactly nothing to your harddisk. But anyways, it is neither advisable nor necessary, any Linux OS is able to totally wipe out your harddisk.

That comment leaves the impression that you think that Ubuntu is always the newest version of Ubuntu. It is not. Any maintained distribution will from time to time release new versions (or will update constantly, so called rolling release). But anyways, if Linux will run fine on your machine is not really depending on the distribution (although Ubuntu is known to be rather bloated) but on the desktop environment you are using. Unlike Windows there are several desktop environments, some rather heavy (Gnome, Unity, KDE), some rather light (XFCE, LXDE, Enlightenment or one of the many window managers).
It would help to know your CPU and videocard specifications to give you a reasonable recommendation which one to use.

Actually, all you need are a few cent for an empty CD-R (or a pendrive if your machine is able to boot from USB). You can download Linux legally for free. Welcome to the world of open source.