Now I am not one to usually do this straight away...... but I think you need to do some of your own research here. First off, Slackware isn't as user friendly as other distro's so if you are confused at the installation, maybe you need to look into this a little further.
Also if you want a faster response, you need to share relevant info regarding your setup. For instance, how many hd's do you have? Are you using linux already? Does Xp use the entire drive or is it already partitioned? Etc