You receive the error, "Computer not Found" or similar error (such as Failed to Resolve Hostname) indicating the target computer's name cannot be found.
This error indicates the computer could not be found or be resolved by DNS or NetBIOS (NetBT). Possible causes for this error include the following:
- The computer does not have an entry in DNS and cannot be resolved by NetBT.
- Manual or DHCP updates to DNS can cause this issue.
- DNS suffixes can also cause this problem. For example, A GPO that sets the DNS suffix search list is not applied to an OU or a particular machine or that the DNS suffix search list is malformed or otherwise misconfigured. This includes using DHCP option 119, which is not supported by Windows clients.
- Another cause for this error, though rare, is misconfigured PTR zone records. Check your Reverse Lookup Zones for correct information and ensure your Forward Lookup Zone records are set to automatically update PTR records.
Ensure the computer name can be resolved by using nslookup or ping. In certain cases, it may be necessary to use the computer's Fully Qualified Domain Name (FQDN) or IP address.
In certain cases, the NetBT (NetBIOS) name will resolve but the FQDN will not. Since PDQ uses the FQDN to resolve, test by pinging the FQDN of the computer (even if ping shows the FQDN, resolution can still be NetBT with the DNS suffix appended after NetBT resolution) and by performing an nslookup on the FQDN, ensuring that both results match.
As a possible example of the above, you run an nslookup for pc.domain.com and the result is for pc.domain.com.domain.com. This means nslookup is unable to resolve the FQDN of the computer and will then attempt to append the default domain suffix to the query. To avoid this and force the FQDN lookup, perform an nslookup and add a trailing dot at the end of the FQDN; e.g. nslookup pc.domain.com. will force a lookup of that as an FQDN without appending the default domain suffix.
In these cases, you can restart the DNS Client service (service name: Dnscache) on the impacted target machine to flush DNS and register the client's DNS record. Also ensure the DNS suffix is correct for the computer.
Additional guidance on troubleshooting DNS issues can be found in the following webcasts:
PDQ Live!: Happy, Healthy DNS - Solving Common DNS Problems
PDQ Live!: "It's Not DNS!" (it was DNS)