Please read Somasegar’s blog where he talked about the past 10 years and how Visual Studio has evolved.
http://blogs.msdn.com/somasegar/archive/2007/03/26/visual-studio-turns-10.aspx

If you have faced problem and getting CRC failed error while extracting March 2007 Orcas CTP .rar files, then you must be following this link. Which has been published on 28-Feb-07 contains 7 .rar files.
http://www.microsoft.com/downloads/details.aspx?FamilyId=281FCB3D-5E79-4126-B4C0-8DB6332DE26E&displaylang=en>

You must download corrcet version from this link
http://www.microsoft.com/downloads/details.aspx?familyid=B533619A-0008-4DD6-9ED1-47D482683C78&displaylang=en date published 27-Feb-07 contains 9 .rar files and it will extract .vhd successfully.

Orcas March 2007 CTP is available.

http://www.microsoft.com/downloads/details.aspx?FamilyID=B533619A-0008-4DD6-9ED1-47D482683C78&displaylang=en