For those who don't have a Dell of that model, you need to list what it NOW has, and what is open inside the case (memory slots, drive space, etc)
Dell Inspiron 546
CPU: AMD Phenom X3 8650
HD: 500GB 7,200 SATA
VGA: ATI Radeon HD 4350 512MB
First order of business is getting one or two additional disks. Don't spend money on a graphics card. The Samsung F3 is a good fast disk.
Thanks for all your help- good karmah coming your way.