There are additional steps to get Exchange 2007 SP2 installed on SBS 2008, below are the steps to complete from Microsoft Support

http://support.microsoft.com/default.aspx?scid=kb;EN-US;973862

Windows 7 allows you to burn ISO files (images) directly with no third-party plug-ins. All you have to do is right click on an ISO, and click “Burn Disk Image”.

My experience was a bit different, had to click “open with” then choose “Windows Disk Image Burner”, but it works as advertised. Too bad there isn’t a way to mount an ISO without 3rd party software, I guess we will have to wait until Windows 8, or W7 SP1??

Need the Hyper-V Manager for Windows 7 or Windows Server 2008?

http://www.microsoft.com/downloads/details.aspx?FamilyID=7d2f6ad7-656b-4313-a005-4e344e43997d&displaylang=en