Based on the keywords provided, you are referencing a specific Cisco IOS software image for the Cisco 2800 Series Integrated Services Routers (ISR).
It is highly recommended to shift away from old, unpacked hardware IOS binaries. Use virtualized images like Cisco IOSv c2800nm adventerprisek9 mz 152 1 link
Also run:
Cisco IOS and IOS XE Naming Convention for Routing Platforms Based on the keywords provided, you are referencing
rommon 1> confreg 0x2102
rommon 2> boot flash:c2800nm-adventerprisek9-mz.152-1.bin
Direct Answer: An official Cisco IOS image file named c2800nm-adventerprisek9-mz.152-1.bin does not exist Cause: Boot variable incorrect or Flash corrupt
Router> enable
Router# copy tftp flash
Address or name of remote host [255.255.255.255]? 192.168.1.100
Source filename []? c2800nm-adventerprisek9-mz.152-1.bin
Destination filename [c2800nm-adventerprisek9-mz.152-1.bin]? [Press Enter]