If you try to install Windows XP under VMWare GSX Server, it will not work by default. The Windows install kicks back saying it is unable to detect any hard drives. This is because VMWare emulates SCSI drives which XP doesn’t have drivers for by default. Luckily it is very easy to get around this problem.
While the Virtual Machine is off, download the “SCSI Disk Drivers” from VMWare (Direct link). Upload those to the GSX Server. Edit the VM’s settings. Under floppy drive select “Use existing floppy image…” and browse to the image that you just downloaded. Make sure to also check “Connect at power on”. Then, power on the VM; just after the XP install starts, stab F6 (when it says so). Once it finishes loading up, Hit “S”. It should highlight an option for “VMWare SCSI Controller”, hit enter and then enter again.
After this you should be able to install just like normal. It is somewhat annoying that VMWare doesn’t have a setup that works by default in XP, but I also blame XP for having an old and crappy setup. Also, to be fair, GSX is generally used for hosting server OS’s, not clients like XP.