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Why Computer Shows Less RAM than Installed
http://www.vistaarticles.com/articles/409/1/Why-Computer-Shows-Less-RAM-than-Installed
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Published on 05/12/2007
 
Why Computer Shows Less RAM than Installed
Why Computer Shows Less RAM than Installed

This is because your computer does not have a dedicated graphics card.

You are using a integrated graphics card built on motherboard which shares memory from the RAM installed.

They can share from 1 MB to 256 MB.

If your computer shows around 1-200 MB less than the RAM installed - its okay, anything more your RAM is not installed properly / working.