You could download one from
http://www.bootdisk.com or if you have a running computer go to control panel/add remove programs/click on the start up disk tab from there you cam make a system disk. Then just boot the machine with this disk it will take you to an a:\ prompt type d:\ then hit enter you wil then have a d:\ prmpt with your windows cdrom inserted type setup.exe then hit enter. You should now be in the windows setup.