Verifying and correcting the DNS settings on the Windows server When encountering DNS resolution problems during Tableau Server setup on Windows, the initial and most appropriate action is to verify and correct the DNS settings on the server. Incorrect DNS settings can prevent the server from resolving domain names properly, leading to network communication errors. Option A is incorrect because changing the domain name of the server is an excessive step before checking the existing DNS settings. Option C is incorrect as increasing bandwidth allocation does not address DNS resolution problems. Option D is incorrect because installing a secondary DNS server, while beneficial for redundancy, does not directly resolve existing DNS configuration issues on the primary server.