Question : Laptop WiFi problem with network connections

I am using a Toshiba Protege M400 on my local network.  I normally use wifi with my Linksys WRT300N router.   The laptop has always had a problem in disconnecting with the wifi intermittently (not often).  

I had changed the IP settings from static to auto using DHCP.  Since I have done this WORD was starting very slow and causing me problems and when the system starts up it is very slow.  At first I thought it was Word.  It is the network settings.  

I have tried to reset it to the static IP address but it still has problems.

I have another laptop and it works fine on the wifi.  I take the problem laptop in question and it works ok when on other networks (i.e. home or wifi cafe).  

Any debug suggestions to find out what is going on?

Answer : Laptop WiFi problem with network connections

I want to close this case because the initial problem is due to a DNS setup and the subject and title are misleading to the solution.