Iphone wont get detected by windows

I have a iphone 3gs and its brand spanking new from the apple store. I got home and my computer wont detect it in itunes or justa at all under computer. I tried uninstalling itunes , new cords nothing seems to work. Ive tried it in both my laptop and desk top both running 64bit windows 7 ult. and neither of them responded i then took it up to apple and they plugged it in and it came right up. So my question is can anyone help me. My cpu is just not detecting it whatsoever. I tried all my usb ports with other things like ext. HD etc. and they start right up but no iphone but the cords are good cuz i can plug them up in the wall and it charges. running ios 4.3.2

While you were at the Apple store why didn't you ask them if it's compatible with Windows 7 x 64 bit? They probably plugged it into a Mac which is why it came up. I know the iPhone 3GS does work with the 32 bit version of Windows. Which version of iTunes are you running? You should be running the latest.