whats the second instance from?
 

Whats this mean?

Unknown Error: mscorlib
at System.IO.__Error.WinIOError(Int32 errorCode, String str)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean useAsync, String msgPath, Boolean bFromProxy)
at System.IO.FileStream..ctor(String path, FileMode mode)
at WindowsApplication7.Form1.GetFileMD5(String FilePath)
at WindowsApplication7.Form1.DownloadExtras()
at WindowsApplication7.Form1.DoUpdates()
at WindowsApplication7.Form1.Timer3_Tick(Object sender, EventArgs e)
at System.Windows.Forms.Timer.OnTick(EventArgs e)
at System.Windows.Forms.Timer.Callback(IntPtr hWnd, Int32 msg, IntPtr idEvent, IntPtr dwTime)The process cannot access the file "C:\Program Files\Sony\EverQuest II\UI\EQ2MAP\images\maps\map_antonica_2_Gnoll_Cave.dds" because it is being used by another process.