Yes, VB.net Express 2008 is available for free…but VB.net and VB6 are *NOT* often friendly with each other. VB.net has a similar syntax structure and was intended to get VB6 programmers in to .net w/o having to relearn everything all over from scratch. But, as far as compatibility–forget it. There was an import wizard that was supposed to bring your VB6 projects over to .net, but with all the errors you receive and have to recode, you are better off rewriting for .net from scratch.
Verdict: if you are a VB6 programmer and are wanting to edit and work with your VB6 programs, forget VB.net. If you are just wanting to *start* programming in a VB-like language and don’t care about VB6 specifically: then go ahead and grab the VB.net 2008 Express Edition for free and start playing.
I’m a VB6 programmer with a tad bit of .net on top, BTW.
Does this help?: http://www.xtremevbtalk.com/showthread.php?t=279336