JGCOBAKA :
The laptop is wireless as well .
Adapter on desktop: Intel Centrino Advanced N6205
Router: Zyxel C1000Z
Distance from router: ~ 10 ft with no obstructions
Open the NETWORK and SHARING CENTER and the CHANGE ADAPTER and highlight the adapter and then Right Mouse Button and select STATUS. The SPEED is what you are interested in. Check it on both computers. Are they the SAME? If they are it would seem that the adapter and router don't like each other or you have a s/w problem?
The Centrino appears to be a 'chip'? I assume it is installed inside the Desktop (http://www.intel.com/content/www/us/en/wireless-products/centrino-advanced-n-6205.html)? If so then I suspect an internal antennae problem. Did you open the case and see if they all are connected? Have you tried re-seating the adapter?
What is the make and model of the desktop? Is it NEW and under warranty?
Does the router have the latest firmware? You need a wired connection to install updated firmware.
I'll assume your desktop has a network connection, can you wire it to the router and check speed to rule out an OS problem?