I have made minor changes to the os. It took some time as I had to learn about that bs (I am a Win 7 newbe). One of them has been disabling the AERO feature embedded in Windows 7. Though I am not 100% sure that Aero was the cause, this week I have not experienced any such video "black out". :-)

I will start looking for a new video card in order to have more RAM for the GPU. But I am no more in a hurry, so that I'll take the time to look for a good deal, so that my PC, my wallet and I will all be happy.

Thanks to all of you.

Hello Beefheart,
could you please let me know if with the aero feature disabled the nvs 440 kept working fine with w7.
many thanks
tn

Yes, since the time I have disabled the Aero my PC has no longer experienced any such inconvenience :-)
As I don't need such paltry feature, I have disabled the aero in all my PCs regardless the video card that is installed.

Many thanks for your kind and prompt answer.
Could you please tell me also which version of the drivers you are using.
thnaks
tn

Driver version 9.18.13.900 dtd 28/10/2013.
In order to avoid the risk of any conflict I have NOT installed the multi-monitor sw provided by nVidia. I just use the Windows embedded feature, and the PC works fine.

I can't find anywhere this driver. I've searched in the nvidia site but no result.
It seems that now all drivers are named in a different way.
Could you help me with a link to download it.
thanks
tn

Your O.S. is Windows ...?

W7 Home Premium x64

Great, I have Win 7 Pro 64bit, so it's the same.

I have found out that my driver is available as
307.45-quadro-tesla-win8-win7-winvista-64bit-international-whql.exe

You should be able to get it here:
NVIDIA Quadro NVS 440 Video Card Driver Download

Alternative: I have uploaded the file for you here (download will be available for 7 days, free service, no need to register):
https://we.tl/6xmehsOJ6z

Hope it works. Regards.