Because 7 8 9.
It doesn't have windows.
Window.
Because 7 ate(8) 9!
Because 10 11 12.
Ans: PASAL, OBOL and BASI
Omega!! Note: surely it already exists but I thought of it independently and am proud of my terrible joke!
Because 7 8 9. (7 ate 9)
Hey Microsoft, why is there no Windows 9? You've given us 7 and 8, and now you're skipping straight to 10?" "Well, to be completely honest, 7 8 9."