I have two 4GB Corsair Vengeance sticks installed, I just recently did a clean install of windows 7, and now it only shows 6GB total not usable, total. dxdiag says 6144MB. What's going on here?
Are you using Windows 7? And you are not using an integrated graphic card? If so, 2 GB is being shared to your integrated graphic card.
It is win 7, and it's not intergrated, I have a GTX 550 TI, but honestly there's somthing funky going on.. I just tested to make sure I didn't have a bad stick, it will boot with BOTH but not ONE. I got it to boot with one the first time I tried, but every attempt since has resulted in a blank screen with no post
(no keyboard flash that I saw), but it's a long press turn off.
First, clean the Gold plated bars thingy (the part where you insert it on the RAM slot) with an eraser. Then one by one, check if which stick is running by inserting each on the Motherboard and turn on the PC. Windows 7 will run with at least minimum of 2 GB. If ever both sticks are not usable and you need them both attached on your PC, I'm not sure but both might have damaged.
I'd use rubbing alcohol and a foam swab or lint free cloth, and eraser can leave traces of itself and cotton swabs like Q-Tips often leave cotton fibers