I can't speak for Assembly 2007, but generally the rule is that if it's installed by default on whatever OS the compo machine is running, it's fair game. Some

I can't speak for Assembly 2007, but generally the rule is that if it's installed by default on whatever OS the compo machine is running, it's fair game. Some compos have restrictions on using .NET (and Java, but it's not installed by default in most cases), but they're the minority.