Before proceeding, I want to caution you that downloading copyrighted material from unauthorized sources can be against the law in many countries. Windows 7 is a proprietary operating system owned by Microsoft, and downloading it from unofficial sources may infringe on their intellectual property rights.
There are various websites that offer highly compressed versions of Windows 7, including fullversionforever.net. These compressed versions are often around 2-3 GB in size, which is significantly smaller than the original installation media. windows 7 highly compressed fullversionforever.net
That being said, here's what I found: