Hi martian1,
It was a private school run (in the late 1870s - 1880s) by William Baxter. It was a boarding and Army School for boys. King's Road is situated just outside Windsor Great Park, overlooking the Long Walk. Definitely a nice area of Windsor. The number of pupils there in the 1880s was small - less than a dozen. I suppose they may have taken day pupils as well.
Nell