Early retail and OEM versions of Windows 95 came on 13 or 21 floppy disks (depending on the edition: 4.00.950, 4.00.950a, or 4.00.950b). The first disk was bootable. The IMG files from this era contain a specific sequence:

Here’s a concise guide to finding, using, and booting a (typically a floppy disk or hard disk image).