I just set up a DNS Server on my windows 7, called SimpleDNS

I added a zone for example sag.com and defined www.sag.com and sag.com to 192.168.1.2 (my Network IP Address) . the problem is when I try to ping sag.com the SimpleDNS logs says that it answered the request with 192.168.1.2 , but the ping doesn't resolve anything . SimpleDNS logs:

> 14:00:43   Request from 192.168.1.2 for A-record for www.sag.com
> 14:00:43   Sending reply to 192.168.1.2 about A-record for
> www.sag.com: 14:00:43   -> Answer: A-record for www.sag.com =
> 192.168.1.2 14:00:43   -> Authority: NS-record for www.sag.com = mehr-pc

nslookup :

> C:\Users\Mehr\Desktop>nslookup www.sag.com DNS request timed out.
>     timeout was 2 seconds. Server:  UnKnown Address:  192.168.1.1
> 
> DNS request timed out.
>     timeout was 2 seconds. DNS request timed out.
>     timeout was 2 seconds. DNS request timed out.
>     timeout was 2 seconds. DNS request timed out.
>     timeout was 2 seconds.
> *** Request to UnKnown timed-out

the DNS server IP is 192.168.1.2 , and Access point address : 192.168.1.1

what should I do?