Studio Microphone - HELP?

I bought a studio microphone , CAD GXL2200 Condenser. About a month ago. I know very little about this type of stuff. I had to go by a 48v phantom power box, also. then I went & bought 2 cords. One to plug from the mic , to the box. then one for the box, to the computer. (usb end) I also downloaded a program called reaper on my computer. but when I hook everything up, & try to record , nothing is coming in. it's silent. I have no idea what to do next. I have tried a ton of stuff . help..

Check the system volume control to make sure the "Line In" volume is up and that it's not muted.