Welcome to the Community,
I'm not quite sure I understand this correctly. Are you talking about an already existing - i.e. previously working - WIndows XP VM, or are you trying to do a fresh installation? In case of an installation, take a look at http://kb.vmware.com/kb/1000863 for details and the required floppy disk image (the latest vmscsi.flp is also located in the VMware Workstation installation directory).
André