Why can't I run these

I have a Nvidia GeForce 9500 GT DDR2 with 1024mb
I recently installed it a few weeks ago after a reformat.

I have Borderlands, COD4 and COD2, Half life 2, CSS, and Gmod

CSS, gmod and HL2 work excellent on my computer.

I did a www.canyourunit.com scan to see if I could run Borderlands, and it says I have full requirments for recommended.

But when I try to run Borderlands its so slow even with all the settings to medium and low, but Half life 2 meets only a few recommended requirements and it goes completely smooth.
I updated my graphics driver fully and yet I can't play COD4, COD2, or Borderlands without a lot of lag.

 

Might be a lack of memory. CSS runs pretty smooth on virtually anything. id try to upgrade your memory to at least 2GB. if anything, youll rule that out if it still doesnt work, and youll have more memory which is never a bad thing.

 

I think that memory is for the vid card. It should be good enough to run the games listed. Try updating directx here:
http://www.microsoft.com/downloads/...FamilyID=2da43d38-db71-4c1b-bc6a-9b6652cd92a3

and what are the specs for the rest of your pc?

 

Especially RAM and CPU... and with that videocard, do you have a strong enough powersupply installed?