Your computer has been severely infected by worm, that is ECTBBYN.DAT. This is quite dangerous and unsafe for your PC and there may be other infections on your PC. You should urgently check your PC and remove any malicious application including ECTBBYN.DAT as soon as possible.

Location : C:\WINDOWS\ectbbyn.dat
Type : Worm
Dangerous : YES
Removal : Immediately

 
How to get rid of ECTBBYN.DAT file / Error message

 
If still have problem, download the HijackThis file and post in the forums for free technical support.
For more information – How to post HijackThis log file?