To backup the DNS server properties:

Open the registry, and go to HKLM\System\CurrentControlSet\Services\DNS\Parameters

Save the content in a .reg file called .\dnssettings.reg

To restore, cleanup the .reg using notepad and restore using regedit /s .\dnssettings.reg

Now, to back up and restore the DNS zones:

If you do not use Active Directory-integrated DNS, you must explicitly back up the zone files.

See here about backing up DNS:
http://support.microsoft.com/kb/304489
http://technet.microsoft.com/en-us/library/cc738755(WS.10).aspx

Additionally: using powershell (http://dnsshell.codeplex.com)

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Backup an AD integrated DNS zone:

dnscmd /zoneexport “zone name” “zone file name”
For example: dnscmd /zoneexport test.local test.local.bak.

The file is automatically created and stored in the %windir%\System32\DNS folder. This can be copied to a more secure location if needed by the administrator.

Restore an AD integrated DNS zone:

The administrator can restore and earlier version of the DNS zone from backup at any time. the following steps outline the process to restore an AD integrated DNS zone from backup in Windows Server 2008.

Rename the backup file extension to .dns.
For example: test.local.bak to test.local.dns

Now, type the below command in the command prompt.
dnscmd /zoneadd “zone name” /primary /file “zone name file” /load

For example: dnscmd /zoneadd test.local /primary /file test.local.dns /load.  This will add the zone to DNS.

Next, type the below command in the command prompt.
dnscmd /zoneresettype “zone name” /dsprimary

For example: dnscmd /zoneresettype test.local /dsprimary. This will reset the zone to an Active Directory integrated primary DNS zone.

In case of zone corruption, perform the below step to delete the current zone before restoring the zone from backup as indicated above.

Open an elevated command prompt (right click on command prompt and select “run as administrator”), type the following command and press enter.

dnscmd /zonedelete “zone name” /dsdel /f
For example: dnscmd /zonedelete test.local /dsdel /f