There is only one HOSTS file.
HOSTS File Location:
Windows Vista = C:\WINDOWS\SYSTEM32\DRIVERS\ETC
Windows XP = C:\WINDOWS\SYSTEM32\DRIVERS\ETC
Helpful Resources:Secure your PC with the HOSTS fileThe Hosts File and what it can do for youBlocking Unwanted Parasites with a Hosts File
Currently, you are using Spybot which as part of its protection, populates the HOSTS file and makes the HOSTS file read only. Personally, I do not use Spybot and like some others, lost faith in it.
I use MVPS Hosts file
to edit/manage the Hosts file.Spywareblaster
to the Windows operating system registry and adds sites to Internet Explorer restricted list. Spywareblaster adds protection against ActiveX based malware attacks. In addition, I use Spywareblaster, as it also protects against known tracking cookies being installed in Internet Explorer and Firefox. Spywareblaster adds thousands of known Malware installing sites to the Restricted sites zone of Internet Explorer.
Spyware blaster Helpful Resources:Using SpywareBlaster to protect your computer from Spyware, Hijackers, and MalwareSpywareblaster FAQs