crosspost from http://rextang.net/blogs/work/
Seems I am not the only one who missed the information while downloading Orcas 2006 Sep CTP and found that I can not open the virtual machine.
I got the problem while opening the .vmc file of this CTP in Virtual Server 2005 R2, it told me:
The parent virtual hard disk "E:\VPC\TimeBombedBase\Base01.vhd" for the differencing virtual hard disk "D:\Orcas2006SepCTP\VSSep2006CTP.vhd" does not exist. Please reconnect the differencing virtual hard disk to the correct parent virtual hard disk.