Please explain me while I try to downgrade ios ver "c880data-universalk9-mz.151-4.M4.bin" to "c880data-universalk9-mz.150-1.M.bin" giving error msg wrong ios image and going to rommon mode. is that possible to downgrade cisco 887 router?
I cannot say this with 100% certainty but usually, Cisco devices allow to downgrade their IOS. Please post the complete transcript of the failed boot attempt. Also add the output of the dir flash: command from the ROMMON. Thanks!