How to initialize 2nd video card on non-SLI mode

[Happy Hopping]

I have 1 video card running for months, I just try to insert the 2nd video card on the motherboard (the 2nd PCI E), when the machine boot up, windows xp pro doesn't sense the new video card, and I don't quite see an option on nvidia control panel to initialize the 2nd video card neither.

what is the step by step?