Perhaps you lack context. At the time navigating and running almost anything under Windows without a mouse was not a problem at all. Being that the OS was relatively new and evolving (transition from W3.1 to W95 era I believe) most everyone using these machines were used to learning and using keyboard shortcuts for everything. So, yeah, Windows users at the office had no problem if we removed the mouse. In fact the prank was pointless because it was almost a challenge to show us they could still function. With Mac users --again, at that time-- they just crashed and burned.

As a side note, this was also the pre-Google Internet era, with super early Linux (can't even remember the version). I remember using NCSA Mosaic!