Do you have just one computer connected to the internet? If so, why would you want a wireless printer? If you have more than one computer you must have a router. Is the second computer connected to the router with a cable? If it's not connected with a cable you must have a wireless router. I have a wireless printer that's connected to my router with a cat 5 cable. Brother told me that it's a more stable connection that way and the printer is only about 3 feet from the router so I connected with a cable and can print from my laptop in a different room.

if you were looking on craigslist don't give up hope because there are definitely some good ones out there, I have been lucky and got great deals, you definitely want to be able to try them out and make sure they run properly and that the copy of windows on them is legit, try going to windows update site with it and have it scan the pc to see if it has any problems, if it is not a legit copy you may find out by doing the windows updates trial. I also always go to belarc.com and let it run on the pc and then view the info it gives about the pc to make sure what they are telling you is really what is in that pc. I also go to the event viewer and look for red flags and to device manager and look for yellow flags.

Just don't try doing this with a regular usb cable!! I prefer to use a usb flash thumb drive to move them if you are not networking them. I never cared much for the usb transfer cables.

A USB adapter is for use in computers that do not have a "built-in" wi-fi receiver. For example, my 5+ year old desktop does not have that ability, just dial-up and ethernet. But my laptop does. So I have my desktop wired to my router via ethernet and use the laptop in another part of the house where it picks up the wi-fi signal. So I'm not sure this is what you need at all.