Have yo checked IP addressing to see if there is a conflict. Even if you are set to auto assign an address this can sometimes happen. To check this:
Connect the laptop.
Open a command prompt.
Execute the following command "IPCONFIG -ALL"
Record the IP address for the WIFI adapter.
Close the command prompt.
Open the Network and Sharing Center (Accesible via Control Panel)
Select change Adapter settings
Right click on the WIFI adapter.
Select Properties
Highlight Internet Protocol IPV4 or IPV6... whichever version you are using
Left click on properties box
Select Use the following IP address
set an address other than the one you recorded above.
set the subnet mask usually 255.255.255.0
set default gateway to router address
Hit...