I downloaded and installed MS IE7 today, and after doing so, I couldn't run any ASP.NET applications in VS .NET 2003.

It would first warned me that the project I was opening was on an untrusted webserver, and asked if I wanted to open it or not. I simply said Yes and that seemed to take care of that.

When I went to run it, it said it couldn't start debugging due to security levels. I had to go into internet options in IE, and change the local intranet zone to include http://localhost

Now everything is working ok.

Not sure if this will happen to everyone, or if it had something to do with my existing settings, but just a heads up incase anyone runs into the same issue.