No the 7300 isant SLI ready.
What is NVIDIA SLI Technology?
NVIDIA® SLI™ technology is a revolutionary platform innovation that allows you to intelligently scale graphics performance by combining multiple NVIDIA graphics solutions in a single system with an NVIDIA nForce® SLI media and communications processor (MCP).
How Does SLI Technology Work?
Using proprietary software algorithms and dedicated scalability logic in each NVIDIA graphics processing unit (GPU) and MCP, NVIDIA SLI technology delivers up to twice the performance of a single graphics solution.
A normal graphics card looks like such
Just a standard, AGP graphics card.
These, are SLI video cards, you can get alot more, 6600, 7800 7900 etc etc, this is just the first ones I found..
So, notice the little notch sort of thing at the top..
Ok, you need two identical cards with this.
You then install the cards, as normal.