ip release/renew may help, but probably won't be a permanent fix. There is an underlying problem with either the laptop or the network. Most of the time when a router is involved, the sudden loss of connection to one machine while the others are fine may be fixed with a firmware upgrade to the router. You just want to be sure to follow the instructions and if you do you won't mess it up. Here is what i found on the netgear website and the latest firmware:
WNR2000 Firmware Version 1.2.3.7
Once you do this, you may have to re-secure the network easily by doing this:
Securing Your Wireless Network: WPA/WPA2 (Recommended)
It is all pretty basic stuff once you see it and do it.