I have code to call a DLL that I wrote in C (see end of message). This code has worked fine for months. I reloaded my OS and installed a fresh vs2005 rc and now I'm getting a System.DllNotFoundException. It also says: Unable to load DLL 'copy.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

My DLL is in my working directory just as it was before. My project setup has not changed and the working directory is specified correctly. What could have changed to cause this error?

Code:
[DllImport( "copy.dll", CharSet = CharSet.Unicode )]
public static extern int BackupClose( long hash1, long hash2 );