This probably means that your server requires you to specify the Windows domain name as part of your username (eg, &quot;DOMAIN\\userquot;). Or you might have just typed your password wrong.
Mae'n fwy na thebyg fod y gweinydd am i chi roi parthenw Windows fel rhan o'ch enw defnyddiwr (e.e. &quot;PARTH\\defnyddiwrquot;). Neu gallech fod wedi cam-deipio'ch cyfrinair.