Hi there fellow IIS7 people. Currently trying to make a rule to rewrite an input like this: getpic.asp?id=216303644&picsize=350 when visiting this adress, I simply get an 404 and the rule does not trigger. I'm fairly convinced the problem lies with the "?" that I had to escape as "...

Yes, that makes sense. The reason why this works with URLRewriting.NET is because it has a logic to fix up the relative path for the ASP.NET application. URL rewrite module does not do that, hence the "~/" - style links become broken after rewriting. One way to fix that is to add the following...