I wanted to do something similar: Debug a simple ASP.net 2.0 web page in Visual Studio 2005, running on my Windows Vista Ultimate 64-bit machine. I added a Debug.WriteLine statement in the Page_Load event handler of default.aspx.cs and sit it as a breakpoint - as I'd done thousands of times before with Windows XP.
I pressed F5 and looked at the code screen, naturally expecting the app to stop on the designated line. And . . . it didn't! I tried again, but still no go. So I shut down VS2005 and cleared all the DLL files from the bin folder and all the files from the obj folder. I restarted it, recompiled, and tried again. Still didn't stop!
Then I did a ton of research and via Scott Gu's [excellent] blog was taken to this page. There are a LOT of steps. After following the instructions in the last one I tried again but it still didn't work! So then I examined this series of articles by Mike Volodarsky. I followed the VS2005 link and carefully went through the steps needed to get debugging working. I didn't actually go as far as running the app through IIS7 as I intuitively couldn't believe that the internal web server in VS2005 wouldn't debug properly in Vista.
I did some more research and came across this ASP.net forum posting. Note that the second fellow, from Lahore, Pakistan insisted to check the web.config file and be sure that debug is enabled. "Of course it must be", I thought. But when I checked, it was not! So I changed it to:
I hit F5 again and ... it worked!! I don't know for sure whether all those other steps were necessary though I think that installing the hotfix was probably a good idea.
In conclusion, I must say that situations like this are all too common with Microsoft development products. This should have been a "5 minute" thing to fix, but I wasted 90 minutes of my time on it. I simply don't accept that such things should be happening from a paid for product built by a multi-billion dollar company.
Though with the introduction of this blog, I hope to help others save countless time in the future by documenting situations like this and having it picked up shortly by the search engines.