Hi.

Is there any way how to play in windowed mode? Thanks.

There is a previous tread on this topic with part of the fix:

For Silent Storm:
Open:
\GOG.com\Silent Storm GOLD\Silent Storm\cfg\config.cfg

and change:
setvar gfx_fullscreen = 1.00

to:
setvar gfx_fullscreen = 0.00

This didn't work for me until I changed the setting to run Silent Storm as Administrator (Windows 7 64 Professional).

HOWEVER, it erased all of my previous saves in the process. Given that I was near the beginning of my first play through, this was no big deal, but beware.

I don't have full windowed capability, in that I still need to use alt-tab to move between programs, but it allows me to use dual monitors with the Walk-through open on the second monitor to advise on perk choices.