Click Start, click Control Panel, click Network and Internet Connections, and then click Network Connections.
Right-click the network connection that you want to configure, and then click Properties.
On the General tab (for a local area connection), or the Networking tab (for all other connections), click Internet Protocol (TCP/IP), and then click Properties.
If you want to obtain DNS server addresses from a DHCP server, click Obtain DNS server address automatically.
If you want to manually configure DNS server addresses, click Use the following DNS server addresses, and then type the preferred DNS server and alternate DNS server IP addresses in the Preferred DNS server and Alternate DNS server boxes.
I would suggest to use OpenDNS instead of your ISP's DNS.