Question : Convert web.config from .NET 3.5 to 4.0

Hi,

How do I choose to convert the web.config from .NET 3.5 to 4.0?

It's happened automatically several times using VS 2010, but sometimes it doesn't ask me and I don't see any 'convert' command.

Thanks.

Answer : Convert web.config from .NET 3.5 to 4.0

The best way is to VS 2010 do automatically for you but looks in your case it is not happening sometimes.
Check this article: http://www.asp.net/(S(ywiyuluxr3qb2dfva1z5lgeg))/learn/whitepapers/aspnet4/breaking-changes
See if you get any errors while migrating and if there is any fix for that in the above article.