Team fortress 2 problems :(

[Phillysoul11]

just got team fortress 2 a little while back but my computer had issues with it....it ran really slowly (lots of lag) and was anything but smooth

when I reduce the resolution it helps a little but it still isn't as smooth as I would like in games of more than 10 people, when the level is big or when the resolution looks half decent...

I am using a laptop and I thought that was the problem so I put it on my desktop with no improvments...

the specs for my lappy are

Toshiba Satellite A215 35822
Windows vista home premium
Display Device:
Name: ATI Radeon X1200
Chip type: ATI Radeon Graphics Processor (0x791F)
DAC type: Internal DAC(400MHz)
Current Display Mode:1280x800 (32 bit) (60Hz)
DirectX version: 10
Processor: AMD turion (tm) 64X2 Mobile tech 2.0 Ghz

any help will be appreciated...

Thanks alot!!