I recently bought a new video card (ATI Radeon Mobility HD 3450, 512MB dedicated memory) for my laptop, cause the one I had before stopped working. the pc won't even boot up.
The card works great, I installed the drivers from the AMD website. My laptop has 2gb of ram memory, but as I was installing adobe reader and surfing the web with google chrome i noticed it was too slow to be a freshly installed windows 7 ultimate 32bit version. I checked in the system properties and found out windows only saw 1 gig of memory!!!
So I rebooted and entered the bios setup. I found out the that missing gigabyte was dedicated to something called Extended Memory. But i couldn't change the value of the amount of memory reserved for it. So now I'm stuck.
Is there a way to modify or, even better, disable it? is extended memory reserved for shared video memory? all this happened after replacing the video card. I had all the 2 gb available before.
Sounds like your BIOS is indeed deciding to share system memory with your video card. Instructions for how to disable that would depend on your laptop, and you can probably find the information fairly quickly with google.