[Upgrade] I need suggestions on what to do first

[Steelshanks]

Going to upgrade the wife's computer soon. Just wondering what the weakest link is on the following list.

• 
  CPU: Intel Core 2 Duo E6750 2.67GHz
  MB: P5n-E SLI
  OS: Windows 7
  RAM: 4GB
  GPU: NVidia GTX 550 ti 1GB
  PSU: 1k watt (I forget brand)

I'm trying to keep the cost under $200. She can run Sims and a few other ARPGs on medium settings with no issues. I was thinking the easiest thing would be to buy another video card and run SLI but I'm not sure if the other parts are going to bottleneck it

 

[someone755]

The PSU is WAY overkill. 400W will be enough.
The processor is way too weak for that GPU. Either switch the CPU and mobo or switch the GPU.
(Aka, you already have HUGE bottlenecks.)

Quote from game-debate.com:
"This Graphics Card needs to be paired with a decent Quad Core CPU."

If you intend to go two-way SLI, you'll even further bottleneck.

I say, get her a brand-new i3 and mobo, that shouldn't be more than $200. And sell your PSU (1kW should get you tons of cash, if the thing is quality) and get another one, 600W still being overkill (but it allows for future SLI, if the new mobo will support it)(at least 80Plus).

If she can already run those games and she doesn't intend to run newer ones, or at a bigger resolution, or at higher settings, why not just leave her be (just please, switch that PSU!)?