That is a scam. Either buy a switch that already has the version you need, or use the community repositories responsibly.
Assuming you have c3750e-universalk9-mz.150-2.SE11.bin on your PC: cisco catalyst 3750 ios download
If you go this route, always run the md5sum of the file against Cisco's official MD5 (found via a quick Google search of the filename) to ensure the file is not corrupted or malicious. That is a scam
is critical for maintaining network security and stability, though the process varies depending on your switch's specific sub-model and current support status. Where to Download Cisco Catalyst 3750 IOS is critical for maintaining network security and stability,
Before downloading a new image, verify what is currently running and what your hardware can support. Connect to the switch via console or SSH. Run the command: show version . Check available space in the flash memory: show flash: .