There is only 1 thing (that I can think of) that would prevent a PC desktop keyboard from working with a PC laptop, the connector. (some keyboards don't like to be crossed between Mac and PCs so I wanted to clarify that you are using the same).
If your Desktop keyboard is USB, then it should work fine being plugged into your laptop. If your desktop keyboard is Bluetooth, it should still work with your laptop so long as it has Bluetooth. Now, if your keyboard is one of those funky old round deals, you're unfortunately out of luck. But fear not, wireless USB keyboards can be had for as little as $20 typically. Just stop in to any electronics store or even just walmart/kmart and the likes.
PS- there's always the empirical option, plug it in and see if it works ;)