Visual Studio 2008 Compile / Trying To Open An Existing App?

I am trying to open an existing asp.net app. on my local machine with VS2008. The app. resides in a folder on the Windows 2003 Server. The app. runs on our intranet. Recently, a change was made to the app. directly by opening one of the files in the solution and adding maybe a couple of lines of c# code and saved back. Of course this would not make a difference as its not been re-compiled.

I copied the whole folder where the app. resides on the server to my desktop and then tried to open the solution with VS2008, it came up with a prompt saying the app was written using a previous version of Visual Studio and needed to be converted to VS2008 format, I followed the intructions, but it failed saying something like "...failed to make a backup etc", it wouldn't open the solution.I have successfully open other apps this way but this one particular one would not just open. All I want to do is to use VS2008 to recompile and publish back to the server. I have tried using VS2005, it just says the app. was created by a newer version of the application...

I think the app was built sometime btw 2004 - 2008. Also, if it is relevant, the folder where the app. resides on the server has a globe icon, don't know if its an IIS thingIs there any other way to compile this .net app. without using VS2008,