My gut says you were jacked by cwshredder or a variant like qhost1. That’s why your dns was changed.
Do me a favor. Click on Run, then type in regedit hit enter. Now, click on edit and then find, and type in nameserverport, and post the numbers it reports, and then type in dhcpnameserver, and post the number it reports.
nameserverport = 0x00000089(137)
There are several instances of dhcpnameserver and no numbers/values which I can see.
They’re all located under: DHCP > Parameters > Options.
Under Options are eight sub-folders:
1, 15, 3, 44, 46, 47, 6 and DCHPNETBIOSOPTIONS
I ran CWShredder and it didn’t find any infected files. Neither did Spybot. Strange.