In the past, you could use a tool called "Heidoc Windows ISO Downloader" or a specific Microsoft "Software Recovery" webpage to input your product key and get a direct ISO.
Windows 7 Professional (32-bit) remains useful for legacy hardware, older software, or virtual machines. However, Microsoft ended in 2015 and Extended Support in January 2020. No official, direct public download exists from Microsoft anymore without a Volume Licensing or Partner agreement. download windows 7 pro 32 bit iso