Wireless PCI card not picking up router

Here's my situation, first I purchased a Dynex Wireless PCI card and it wasn't picking up a signal to the router in our house. I tried resetting the router, reseating the PCI card, putting the card in a different slot, nothing worked. Meanwhile my roommates receive the signal fine on their laptops (even in the room where my desktop is), and my TiVo also is able to connect using its wireless receiver. So I decided to exchange the Dynex for a Linksys WMP54G Wireless PCI card, and I'm still not able to pick up the signal. My desktop PC is using Windows Vista, any ideas??

maybe your desktop is having some problem or the signal is not strong enough.

sounds like the signal from the cards's antenna is getting blocked. Happens alot, especially if tower is on floor. You will need something like this Buy Wireless antenna,WiFi Antenna,2.4Ghz 5Ghz Wlan Antenna,RF connector,RF pigtail cable,Lightning Protector,802.11 a/b/g, Omni ,panel ,yagi ,Grid antenna

Doesnt need to be exactly this but similar. You will also need a length of cable to connect the two