Error while trying to run project: Unable to start debugging.

I am running Windows Vista on which I have Microsoft Visual Studio 2005 installed on. I had been working on a project without any issues. I had to reboot my machine, in order to complete a new application installation and later the problem started.
From the time I rebooted the machine, when I try to run the project, it comes up with an, unable to start debugging error.
There was no change made to the project and I am confused of how to resolve this issue. Any ideas on this?
Microsoft Visual Studio
Error while trying to run project: Unable to start debugging.
The system cannot find the file specified.
