I bought a week ago a D-Link Dir 600 router. Everything works fine as long as I connect the computers through LAN, but I have problems connecting to the wireless network. My laptop gets disconnected every 4-5 minutes. Any idea how can this be fixed or what could cause the problem?
I don't know that it's true in your particular case, but in some instances when a router is capable of wireless-N and only some of the clients are N capable a frequent disconnect issue surfaces for one set of connection types until they are forced to A only, B/G mixed, or N only. The solution for me most frequently was either upgrade all devices to N or set the capability level of the N devices to lower standards.
This problem is less evident in >=2+2/MIMO devices because in some instances they can have their different ins/outs on different frequency bands. Ultimately, I think it comes down to different vendors dealing with band selection differently.