|Web cams don't need much power.|
As long as it's plugged into a USB port directly connected to the mboard (it may not work properly when plugged into an external hub or into a front port on a desktop case), the software is installed for it properly according to the directions that came with it, and it's cord hasn't been damaged, you should have no problems with it.
....the software is installed for it properly according to the directions that came with it....
Usually you DO NOT plug in a more sophisticated USB connected device such as a webcam, printer, or scanner, until AFTER you have installed at least some of the software for it.
DO NOT use Found New Hardware to install drivers for a new device unless the installation directions tell you to do that. In most cases, if you install drivers that way, the device, or it's associated software, or both, will NOT work correctly.