If Windows 7 runs open DNS resolver, we can avoid it by setting up Windows firewall. Please follow these steps.
In the left pane, click Inbound Rules.
In the right pane, click New Rule.
Click Port
Click Next
On the Protocol and Ports page, Click UDP.
Click Specific Local Ports
Type 53 in the text box
Click Next
On the Action page, select Block the connection.
Click Next to continue
Select all the profiles available for different type of connections (Domain, Private and Public).
Click Next
Give a name of the rule, Let me use “DNS_resolver” for example.
You can add description to the new rule (optional)
Click Finish