Cisco password recovery

I have a cisco 1605 and i dont remember the username and the password for it as i have tried many combination to it. and it dosnt wrk . is there a way to go through it becouse i cannot flash the router as it has a lot of security and settings in place and which will loss all my effort in the drain and which i do not even recal wht setings i have . if there is a way about this kindly help