Second monitor not working on XP

Hello,
I have new HP compaq 6910p with win XP SP2 . Everything is working fine, except when I got an S-video cable today & tried to connect it to my TV. In Display properties, it doesn't show the 2nd monitor at all (there are no '1' & '2' for 2 monitors). I checked the display adapters in Device manager & only a LogmeIn mirror shows up there. I went to the HP site & downloaded the driver specific to this model of Laptop - ATI radeon. When that is installed, it says driver couldn't start :-( . I tried to add hardware manually (Ctrl Panel > Add h/w > choose manually from list) & choose ATI drivers - Rage pro / XL / XC / AGP / PCI - nothing works :-( . I have the exactly same model of HP laptop from my work also - it shows ATI radeon X2300 driver & the display dual monitors function is also working fine on this one. I'm not sure what's wrong with my personal laptop. Can someone help ? I've tried downloading another similar ATI driver available from driverscollection.com - specific for this 6910p laptop, however nothing works.