C3900-universalk9-mz.spa.157-3.m8.bin ((link))

To ensure the file was not corrupted during transit, calculate its MD5 checksum and verify it against the MD5 hash provided on the Cisco Software Download portal.

Always verify the MD5 hash of the transferred file against the official hash provided on the Cisco Software Download portal to guarantee the file wasn't corrupted during transfer: C3900-universalk9-mz.spa.157-3.m8.bin