1.6 ghz is kind of pushing it, but it's dual-core so you might see some increase if you enable multithreading.
Start with an FPS config like this one:
http://www.gotfrag.com/tf2/forums/thread/322476/Before you even start the game, open Task Manager and kill unnecessary services, and right-click Steam and set it to 'Low' priority. Then right-clikc explorer.exe and kill it. Your desktop and taskbar will disappear, but you can bring Task Manager back up and run explorer.exe again after you're done.
I like these launch options:
-dxlevel 80 -width 1280 -height 800 -novid -console
Only run TF2 with "-dxlevel 80"
once. Before you play it again, remove that line. If you don't, the game will reset the graphics settings to the DX 8 defaults every time you start it. Set -width and -height to your screen's native resolution. -novid disables the Valve logo video, which shaves a few seconds off the load time. -console just enables the console.
Once it's started, enter these console commands one at a time:
dsp_slow_cpu 1
r_eyemove 0
fps_max 30
r_eyegloss 0
There are literally hundreds of console commands you can tinker with to squeeze more playability out of it, but these plus the config file should help a lot.
Adding more RAM to your laptop (get it to 2 gigs) will help too, both for gaming and general use. Also check the BIOS setup utility to see if there's a way to give the graphics chipset a bigger chunk of the shared RAM.