- source: http://blogs.msdn.com/pandrew/archive/2007/10/25/how-to-upgrade-from-net-framework-1-0-to-net-framework-3-5.aspx
- First upgrade your code from .NET 1.0 to .NET 1.1 using Visual Studio 2003. It has a project upgrade tool with some assistance.
Next use Visual Studio 2008 to upgrade the project from .NET 1.1 to .NET 2.0. The upgrade wizard here does not change your code. It will show you warnings for things that you have to change but you will have to go change them. You also have to fix all your new compile errors and do a full retest.
Once you're at .NET 2.0 the migration to .NET 3.0 and .NET 3.5 is easy. It's primarily just about using the new features available in these new versions of the framework. All your existing code should work fine, in fact you most likely wont even need to recompile.
The .NET 1.1 -> .NET 2.0 breaking changes are detailed here: http://msdn2.microsoft.com/en-us/netframework/aa570326.aspx
Here's a helpful blog entry from Brad Abrams on upgrade experience:
Here's another great post on this topic deom Daniel Moth:http://www.danielmoth.com/Blog/2007/10/migrating-from-net-framework-v1x-to.html
So, I guess they make the transition from 1.0 to 3.5 look easy. Just hope I never have to do it. <^_^>