This right here is your issue (although if you have no other recourse the steps potis outlines above will help a little).
With Nvidia, anything lower than GTX x60 (where x = series, like 560, 460, 260 etc) is pretty much for playing indie games, or games made at least half a dozen years ago. Anything below this, 550's, 525's, 240's, whatever, avoid. GTS and GT models are usually budget cards too, avoid.
I had a GTX 260 until a week ago, and I could run RIFT with most settings on High and get 25-35fps easily. If the model number ends in 60 or higher, it's a powerhouse. Check my sig, you will note both my PC and my laptop follow this theme, both are GTX 560 models.
If you can at all arrange it, return or sell the GTX 545 and get a GTX 560 (if possible the GTX 560 Ti model) which is roughly 2.5 times as powerful and will open your eyes to the beauty of gaming