Mark Russinovich is a Technical Fellow at Microsoft and I don’t have to tell you he’s a windows internal guru…right?
Have published a very detailed article at Technet Magazine about Vista’s UAC… go check it out.

On this page from the Microsoft site where you can find great documentation about Windows Vista, you can also find a document about the http.sys driver

On the site codeproject.com I found a great article with some very good tips for you developers out there to speedup your ASP.NET applications.

I recently found an article from an ASP.NET debugger with some good info about the differences in memory consumption of 64-bits machine vs. 32-bits machines