You don't have to create a boot CD by yourself, you can download it from VMware.
on "Support & Downloads" select "Product Downloads" -> "VMware vSphere 4"
select "VMware vCenter Server 4 Update 1"
right to "Components" click "Show details", this will show you what you ar able to download using the above "Download" button
--> direct link: http://www.vmware.com/download/download.do?downloadGroup=VC40U1
André