Disclaimer: This post is for educational purposes. Always respect software licensing agreements. If you are deploying in a business, buy the support contract.
That is a scam. Either buy a switch that already has the version you need, or use the community repositories responsibly. cisco catalyst 3750 ios download
show version Look for the line: "System image file is 'flash:/c3750-...bin'" . If the switch boots, you already have the IOS. You can back it up via TFTP: Disclaimer: This post is for educational purposes