Find out what type of card goes in, and if there is internal antenna connection.
Look at the support page of the Laptop, most of them provide technical info about the issue.
Internal Wireless cards for laptops are OEM cards and can be found on ebay go for $10 and are very easy to install.
Otherwise get a USB Dongle.
P.S. Make more sense to post the model of the laptop , rather than the Not going to used desktop.