I've been trying to boot into WinPE 4.0 on workstation 8 but it hangs on anything older than Windows 8. I've tried about 20 different machines on 5 different hosts. Only my Win8 (UEFI and BIOS) guests will load; all others just hang while "Windows is loading files...." This works just fine on real hardware, just not inside of vmware. The issue is reported for ESXi on http://social.technet.microsoft.com/Forums/en-US/mdt/thread/4babb5f7-857e-41e7-955a-39ac3cc67b3e, where the solution was to override the BIOS with a different ROM file. I tried it and it wasn't working in workstation, and was hoping someone could post a new ROM file for workstation in case that works. My Windows 7 UEFI machine passes this point, although it has a different issue.
Most of my images came from an older version of workstation, but I've upgraded them to work with only Workstation 8 and newer. I also tried creating new and reimage old image on top of new image, but no prevail. A co-worker also has only used Workstation 8 and also has the issue. I'm guessing it's the guest BIOS.