Core Issue
These messages are caused by the improper use of the boot system command.
Resolution
To specify an image for the router to use when booting, use the boot system flash:[filename] syntax.
Note: There are no spaces in flash:[filename] to specify the filename of the Cisco IOS image to be loaded, as shown in this example:
Router(config)# boot system flash:c3640-is-mz.122-12a.bin
For more information on the use of this command, refer to CFR Commands: absolute - clock timezone.