Helping people with computers... one answer at a time.
Depending on what you're planning, you can use a second wireless point to extend your wireless network.
Can I use a second wireless access point to extend my wireless network?
It depends on what you're planning.
If your access points will be wired together, you're probably okay. But if you're looking to use the wireless access point to avoid more wires ... well, as odd as that sounds, maybe not.
If you plan to have both access points wired together, and perhaps placed a fair distance apart then this should work. This diagram illustrates that scenario:
The important thing is that the access points are actually wired to each other and, say, your internet connection.
On the other hand, if you want to connect some computers and the internet to one wireless access point, and then connect some wired computers to the other access point as in this diagram:
And you're expecting the access point to access point wireless connection to act as a virtual extension cable then this will probably not work. Access Points typically do not communicate with each other.
A better approach for small installations might be to set up a computer with both a wireless card and an ethernet card, and then use connection sharing to share the wireless connection to other computers on the ethernet connection. The only drawback here is that you stand a good chance that these other computers will essentially be "double NAT-ed" - which means that they are effectively behind two NAT routers. The bottom line to that is that some software will not work, and there's a slight performance penalty.