I have found an excellent resource on understanding Windows
Application concepts and exam 070-306.

http://technical-talk.com/mc/mcsd/mcsd306.asp

Spot the Bug: Fun Concurrency Bug
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Can a .NET 1.1 app run on a PC which have .NET 2.0 installed only?
What is type safty in dot net?
Testers & Reviewers Needed for Open Source .NET Project