This is the April 1993 Beta but Microsoft forgot to change the wallpaper and still says March 1993.
The last few icons are now also in 3.1 style and during setup you get a warning if you want to change the Display, recommending you to change it afterwards.
Patch for Pentium II and newer CPU's
This build has a problem installing on Pentium II and newer CPU's, follow the guide linked below to install it.
There are more images available in the gallery.