I confess: I'm breaking the first rule of blogging and talking about something I know nothing - literally, nothing - about.

When I first started this blog, lots of people were asking about Transactional Registry support.  I guess somebody in MS agreed, because that project has been under development for some time now.  It integrates with Transactional NTFS via KTM - the Kernel Transaction Manager - so that a single transaction can encompass both file and registry operations, and commit or rollback those changes together.

This is primarily designed to provide atomicity to application installs and updates on Longhorn; as always, creative uses are welcome and encouraged.

Update: Oh, I wanted to mention this.  What this means is NTFS and Registry calls both understand the concept of Transactions.  Who knows what will tomorrow? It's a good idea to remain in a transaction for as short a time as possible; switch to a transaction, do your work, and switch out again.  You never know, somebody might want to read your setup log.  And you don't want to have your newly-transacted-UI in 2020 rollback on you if the install fails...right?

If you have some really cutting questions you'd like to ask about this, shoot.  Bear in mind I have no idea how to answer them, so if they're really good, I'll chase up an answer for you.  Happy coding :)