You may not be able to use the stabilizer on video from a still camera, Lillian.
Welcome to the forum.
I do not use the Stabilizer Effect in PrE, so might be missing something important, but that 3GB of RAM is about the very bare minimum, just to run Win7-64. Many Effects take some good resources to run, and I wonder if you are asking for more than the system can deliver. About 12GB of installed RAM is recommended for Win7-64 and a Video editing program. How much RAM will your MoBo allow you to install?
videocart is NVIDIA Geforce 8600 GT with update for 64 bits.
The latest driver for that card is 285.62WHQL at http://www.nvidia.com/object/win7-winvista-64bit-285.62-whql-driver.html
If that is not the version you have installed then update it. You should also update your sound card drivers and install the latest version of QuickTime player.
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