Pci slot not working

Hey,

I have a bit of an off situation here. My first pci slot is inaccessible (because of a new video card. The card is not in yet) but works fine. My network card allows me to connect to the internet and everything. My other slot doesnt work. When i put my network card in it, it doesnt give me a list of wireless connections or anything. It used to work a week ago before i had to replace my old video card. It might be my power supply, i only have a 300 watt one in now, but im replacing that today to 550.