The right way to fix the bottom of UPVC windows?

[STEVEROG]

How is the bottom of a UPVC window supposed to be fixed to the brick or blockwork underneath?

I've noticed that several window installation company web-sites suggest that you must not drill through the bottom of the window profile to fix the bottom of the window down. If you can't do this what are you supposed to do, especially if the window is wide?

???

 

[s60tsy]

seal\mortar up afterwards, shouldnt matter how wide it is, when i fit a conny for example i dont screw down to brickwork

 

[STEVEROG]

Cheers for the reply.

What if its a coupled set of doors and windows like a large french door plus windows either side?