Dll replacement issue (riddle in the dark)

The following scenario happens to me both on windows services and we开发者_如何学编程b working with ASP.NET application using IIS. I have an application that I want to change its behavior after it was deployed. So to do that I kill the application process (iis worker process) or stop the windows service. The I rename one or more of its dlls to be with the extension old. Then I put the dlls that I want to replace the original dlls. When I launch the application the original dlls and not the new ones are used (the dlls whose extension is old). I will be happy if someone can solve this riddle for me. Is it some cache I will have to clear to succeed?

I am using .Net Framework 2.0 if that helps you.

Yes, there is a dll cache used by ASP.NET that you should consider clearing. On my system it is located here:

C:\Windows\Microsoft.NET\Framework\v3.5\Temporary ASP.NET Files

Your's will probably be in a similar location, varying by .NET version and whether the machine is 64bit vs. 32bit, etc.