Upgrading .net web app from .net 1.1 to 3.5

I have been tasked with upgrading a large web application from .net 1.1 to 3.5.

I have converted it using Visual Studio 2008, and it compiles ok.

Should I be expecting everything to work correctly straight off? And if not can anyone suggest what are the major pitfalls I should be looking out for.

Should I be taking the time to write and carry out a full test for the entire system, or is that 开发者_JS百科overkill?

To be honest, you're lucky it's converted and compiled without errors! I've had right nightmares with the VS 'conversion' tool in the past.

As for a full test, I'd say that depends on what the effects of errors would be. If it's a personal blog, don't bother. If it's a stock trading system then yes, I'd test it to within an inch of its life!

The main things I'd be looking for are:

• Database connectivity (managing connections, efficient use of Data objects etc. - there are plenty of things that weren't available in 1.1 that might be more efficient)
• 3rd party/external DLLs behaving as expected. They may compile, but do they rely on 1.1 idiosyncrasies?
• Refactoring inefficient code - this is probably the most worthwhile yet most time-consuming. There are so many new ways of doing things 'right' that it will be worth scanning an eye over what the converter's produced and trying to improve on it.

not overkill at all, a lot has changed in 2.5 versions. why not go all the way to .NET 4?