Asp.net - What Does The .net 1.1 To 3.5 Convertor Do?

Just converted my .net 1.1 code to .net 3.5 for my vb.net web app using Visual Studio 2008.I've just compared the old version to the new, and- apart from changing has every references to the Global.asax file changed from Global to [Global] (why!?)- the code itself doesn't seem to have changed at all.

Yet the convertor creates backups for every file, which leads me to believe it can sometimes make significant changes.So what exactly does the convertor look for, and what can it actually change?