CS:S Source Engine has me stumped. How do I get it faster?

OK, I'm getting really annoyed with Source Engine. My system is 1.7 GHz, 2 40GB HDs, 1GB PC133 RAM, and an AGP nVidia 5200 FX (DX 8) with 256 MB of video memory. Now, here's the interesting part. I only get about 2 FPS, but I have total overkill and run on lowest settings. I take this game, put it on a 1.6 GHz Laptop with 60 GB drive, 512 RAM, and 32 MB video RAM integrated nVidia (DX 8), and I can get close to 45 FPS on lowest settings. Both times, I was using a wireless network at 54MBs and good quality connections. Anyone know what I should do, or if not, what starting parameters I should use? Thanks in advance!