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