This is a blog entry that I've been trying to find time to write for the last week.  Unfortunately, the push for GA-day has been all encompassing.  In any case, the news that Windows Marketplace would deliver Windows Vista (and Office 2007 too!) electronically went a lot bigger than I expected.  I suppose the fact that the news was carried by the Associated Press should have made it clear that things were going to go big.  Trevin actually captured the press coverage a bit better than I did.

Out there I found comments at a couple places where people speculated that Windows Marketplace would be distributing ISO images of Windows Vista and that the customer would have to burn the ISO image to a DVD before installing to Windows Vista.  That is the way that MSDN distributed the Betas and RCs to developers but is not what we are releasing from Windows Marketplace.  For Windows Marketplace, we wanted a solution that would not require special hardware (DVD burner) or knowledge (how to use DVD burning software to burn an ISO image).

When you buy Windows Vista from Marketplace you will be able to download three files: VistaSetupPrep.exe, boot.wim and install.wim.  The two .wim files are the bulk of the download (for the 32-bit version they are ~116 MB and ~2.2 GB respectively) and contain the stuff that actually gets installed.  VistaSetupPrep.exe is smaller (for 32-bit this is ~74 MB) and contains the files necessary to actually do the install.

I highly recommend using the digital locker assistant to download Windows Vista.  The digital locker assistant handles three very important steps for you.  First, the assistant has the ability to resume the download of files should your download be interrupted for any reason.  If you do not use the digital locker assistant and your download is interrupted then you will have to start the download over from the beginning.  Second, the assistant will verify that the files were properly downloaded when complete.  Since Windows Vista is composed of such large files there is a chance that corruption can occur while the files are in transit.  The digital locker assistant verifies the files before launching the install and that improves the chances of a successful install the first time through.  Finally, all three files have to be downloaded into the same folder.  The digital locker assistant ensures that files stay together.

After all of the files are downloaded, you can launch VistaSetupPrep.exe (or simply click the "Install" button in the digital locker assistant).  VistaSetupPrep.exe then extracts the 500+ files compressed inside it and links the .wim files into into a folder called "Vista".  The end result is that the Vista folder is a replica of the Windows Vista DVD.  Before VistaSetupPrep.exe exits, it launches the setup.exe in the Vista folder and Windows Vista setup starts, just like if you had launched it from DVD.

That's it. 

For the last week and all of this weekend everyone on the Windows Marketplace team has been downloading Windows Vista and Office 2007 from our internal test servers and installing on our computers at home.  I have to say it's been a proud moment for me.  Repeatedly people on the team have remarked, "I was amazed at how smooth the whole process was.  It just worked."  I worked on the Windows Vista setup team for two years before joining Windows Marketplace to (quickly) develop the system for distributing Windows Vista via ESD.  Let me tell you, there is nothing a setup developer likes to hear more than "It just worked."  I hope you enjoy it too.