Right-click the "My Computer" icon and click "Properties". If it says "Microsoft Windows 95 4.00.950 B", then you are running the updated version of Windows 95 known as OSR2, or its tweak, OSR2.1.

AFAIK, this was the first version of Windows to introduce the FAT32 file system, and the first version of Windows 95 to be remotely stable and usable.

Unfortunately, it is an OEM-only version, so if you have an older Win95, you're screwed (stuck with Service Pack 1).