Error: The process cannot access the file because it is being used by another process

Hello,

I am getting a:

The process cannot access the file because it is being used by another process

error message.  How do I handle this problem?  Below is my code:

public static void MoveFile(string fileName, string destinationFolder)
{
   try
     {
        string source = Path.Combine(Constants.CompleteStagingFolderPath, fileName);
        string destination = Path.Combine(destinationFolder, fileName);

        File.Copy(source, destination, false);
        }
        catch (System.IO.IOException ioEx)
        {
           System.Guid guid = System.Guid.NewGuid();

           if(ioEx.Message.EndsWith("already exists."))
           {
              string source = Path.Combine(Constants.CompleteStagingFolderPath, fileName);
              string newFileName = fileName.Insert(fileName.Length - 4, "_v" + DateTime.Now.Hour.ToString() + DateTime.Now.Minute + DateTime.Now.Second);
                   
              File.Move(source, Path.Combine(destinationFolder, newFileName));  <===Generating error
              }
         }
         catch (Exception ex)
         {
             //do something else
         }
}


thanks