I'm for adding the following rule to Good Tagging frame;
Don't tag with two separate tags (general and specific) when they can be merged into one specific one.
not windows and xp but windows-xp
not boost and asio but boost-asio
There's plenty of tag space to allow a generalisation (which it might actually be if the user isn't familiar with other versions) and some specificity.
I can be quite interested in IIS questions in general on SO/SF and would rather not have to check each specific tag (now that we have IIS4,5,6 and 7).
There's no harm in tagging with a generalisation and a specific version.
As long as it does not get confused with alternate tagging conventions such as using a broad category (such as "sql-server") along with a more specific tag ("sql-server-2005"). This convention allows for people to subscribe to a general tag but still be able to gather enough specificity about the question.