Just installed this via GOG and when I run it the game seems to open but it lowers the resolution of my monitor, which is 1080p, and offsets the game making it unplayable.

Any ideas how I can fix this?

My rig is...

i2500K OC
MSI 980 GTX OC
8Gb Ram
Win 7 Pro

Thanks guys!

Open your nVidia control panel and set it as per attached image.

Outstanding, it worked perfectly! Many thanks indeed!

Some questions though...

Is it known if these altered settings cause any issues with other games (both new and old) or should I make them only when I play Icewind Dale?

Also I've just noticed that after testing if Icewind Dale worked, the settings have returned to their previous values, should that happen?

Thanks again :)

Those settings should be your default, there should be no issues with other games. If the settings have reverted, maybe you didn't press 'Apply'? If you set your video control panel, it should not change unless you change it.

Strange, but now whenever I make the changes and press apply, it literally resets the settings immediately afterwards. Any ideas?

Download this display driver uninstaller. Boot into Safe Mode and run it. Follow the instructions and your nVidia display drivers will be cleanly removed. Boot back into Windows normally and re-install your drivers, which should fix things.

I also had this problem which was connected to the monitor settings. Full details of what I did are in this thread http://www.gog.com/forum/baldurs_gate_series/aspect_ratio_settings_problem/post8

Hope this helps :)