Network Help

Hi, I'm having a problem with my home network which is setup as follows:
Cable Internet modem to wireless linksys router
1 desktop connected wirelessly to network, 2 laptops connnected wirelessly, and a network hard drive cat5'd into the router.

All my computers can access each other's files and printers except for one of the laptops. Everything was working fine, but suddenly, it is as if my laptop disappeared from the network. It's on the same workgroup and everything and I still get internet on my laptop, and, I can access other computers' files and printers. When I go to My Network Places, it only shows folders from the other computers and the network drive. Then, when I go to Workgroup computers, it only shows the desktop, the other laptop, and the network drive.

What can I do?