Some transaction related sample code using Indigo is shown at http://winfx.msdn.microsoft.com/library/en-us/indigo_samples/html/1a9842a3-e84d-427c-b6ac-6999cbbc2612.asp

Assuming that you already have the latest released WinFX build installed ( http://www.microsoft.com/downloads/details.aspx?FamilyId=CE888B4C-CCBD-452F-9D90-F4B7190CCA24&displaylang=en ), you should also install the MSDTC hotfix from http://www.microsoft.com/downloads/details.aspx?familyid=32187993-4736-4A06-97C7-1282B67E3137&displaylang=en so that you can use the new WS-AtomicTransaction protocol. Andy shows the necessary steps to install it at http://blogs.msdn.com/distilled/archive/2005/06/23/431821.aspx