The file you've mentioned, "c3745-adventerprisek9-mz.124-25d.bin", appears to be a specific Cisco IOS image for an Cisco 3745 router. Let's break down what each part of the filename typically represents and then provide a guide on how to work with such a file.
The to configure a basic VPN or OSPF area on this image. Instructions on how to add it to GNS3 or EVE-NG . Let me know what your end goal is for this specific file!
Treat it with respect, use it legally, and never forget: behind every great network engineer is a stable IOS image that never let them down during a lab exam.
: Use this on the interfaces connecting to other routers in the MPLS core.