|"if I wanted more storage could I set it to slave and it work with Windows Vista?"|
As long as you realize that it's old, slow (5400RPM, 512k buffer) & has a small 9.5GB storage capacity (after formating). You'd probably be better off getting an 8GB jumpdrive for about $15.
Being that you have a Vista machine, you probably only have one IDE channel. That means you will have to slave it off the CD/DVD drive. Do not set it up as the boot drive! Just format from either "My Compter" or use Disk Management.