Black and White, what it's all about as far as security settings
What SpyBot (SB) does (as well as SpywareBlaster) is add what ever you do in SB into the specific browser. What "immunization" does is place "undesriable" or what SB considers "bad sites" into the "restricted sites" in your browser(s). Whatever you have in your SB "whitelist" will be placed in the "trusted sites" of your browser(s). I agree with you that if you are "unprotected", as far as I understand it, SB should be removing those sites from the "restricted sites" of your browser(s). What I have found with SB is that if you use the "immunization" in SB it "immunizes" even when you would expect it would not (at least this is the case for the FF browser).
You can apply changes directly to these settings in the browser by going to either the "trusted sites" or the "restricted sites" of your browser(s) security setting.
I don't use Internet Explorer 7 (IE7) but I do use IE6. For IE6 it is Tools>Internet Options>"Security" tab> at that point the user can select either "trusted" or "restricted" sites which are equivelent to "blacklist" or "whitelist" in SB, respectively. As I understand it SB is a "passive firewall" for "undesirable" or "risky" sites that are considered potential "spyware" which is basically supplying the user an interface to use the database that SB has created to access the "security" settings in their respective browser(s). Without SB the user would have no idea which web sites were "bad" and would thus be at risk of visiting any one of them before they could know they were "bad" in the first place.
Using IE6 when the user selects for example "restricted sites" there is then a button that is "enabled" which allows the user to access these sites. At that point the user can "add" or "remove" these sites. By selecting an site (clicking on it) the "remove" button is enabled and the user can remove the site by clicking on the remove button. (the sites are alphabtical thus easy to find).
Check and see if these web sites you are having trouble with are in this "blacklist".
The "blacklist" can also be accessed using SB which in turn does the same thing as either "adding" or "removing" web sites to the list "blacklist" in your browser(s) just as you can also do in the "whitelist" in SB as well as far as making changes to your browser "whitelists".
It entirely up to you if you want to use SB to access the "white lists" or "black lists" which is probably better to do since you are using SB. But in the case of a problem the user can get right to the source by accessing these lists directly in their browser(s). Remember that if you do anything with SB as far as "immunization" is concerned it may then change whatever you have done directly in your brower(s) settings directly in the "white" or "black" lists.
I HAVE DESCRIBED MY BROWSER WHICH IS IE6 TO GIVE YOU AN IDEA HOW what you are asking about works. In your case as far as IE7 the security settings will be different but the concept as far as of how it works about the same.
You can take a look at this link (it is probably the best bet for you at this point):
http://pcsupport.about.com/od/fixtheproblem/ht/ie7securitydef.htm
Basically it describes a way to reset your IE7 SECURITY SETTINGS:
Resetting Internet Explorer 7 security settings to their default levels.
Here's How:
Open Internet Explorer 7.
From the Internet Explorer 7 command bar, choose Tools and then Internet Options.
In the Internet Options window, click on the Security tab.
Below the Security level for this zone area, and directly above the OK, Cancel, and Apply buttons, click the Reset all zones to default level button.
Click OK on the Internet Options window.
Close and then reopen Internet Explorer 7.
Try again to visit the web sites that were causing your problems to see if resetting the Internet Explorer 7 security settings on your computer helped.
You can also take a look at this link provided by MS:
http://support.microsoft.com/kb/923737
There is much more detail available but again part of this links talks about "RESETING" the security setting on IE7. Note that this link speaks of how to "recover" IE7 back to "original" settings as also described in the link above as well.
Windows Internet Explorer 7 for Microsoft Windows XP and Windows Internet Explorer 7 in Microsoft Windows Vista have many security enhancements that make Internet Explorer 7 less susceptible to spyware and to malware. Typically, badly written add-ons can affect the browsing experience in Internet Explorer 7. RIES enables Internet Explorer 7 to recover from such situations.
To use RIES in Internet Explorer 7, follow these steps:1. Click the Tools menu, and then click Internet Options.
2. On the Advanced tab, click Reset.
3. In the Reset Internet Explorer Settings dialog box, click Reset.
4. When Internet Explorer 7 finishes restoring the default settings, click Close, and then click OK two times.
5. Close Internet Explorer 7. The changes take effect the next time that you open Internet Explorer 7.
Note If you cannot start Internet Explorer 7 for some reason, use RIES from Internet Options in Control Panel.
RIES restores the default settings of the following features:
• Home pages
• Search scopes
• Browsing history
• Form data
• Passwords
• Appearance settings
• Toolbars
• ActiveX controls
You asked about "hosts" file.... let me touch on that as well....
Another approach you could take is to address your "hosts" file. But I would say that usually when the "hosts" file is "corrupted" the problem shows itself by not accessing the web site at all rather than just changing the web site. However if a web site has similar "linked" sites that have an address matching the "corrupted" web site I suppose maybe it could appear like the web site has changed simply because it is "addressing" another "related" URL address.
As far as the "hosts" file this file keeps track of the URL addresses of web sites that you have visited. In each operating system (OS) it is located in a different path. I use WIN98SE and it is located in the directory path of Windows> where you find the "hosts" file. In my OS there is no extention on the file, that is to say you will only see "hosts" as opposed to how other files will look i.e. word: myfile.doc. The "doc" is the extention to the file, the "hosts" file has no extention. If you find files with "extentions" that are named "hosts" these are NOT the hosts file that your system uses.
The location of "hosts" for Windows NT/2000/XP/2003/Vista: %SystemRoot%\system32\drivers\etc\ is the default location, which may be changed. The actual directory is determined by the Registry key \HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DataBasePath.
Another option you can take if all else fails is to "rename your hosts file", say to "savehosts" or "oldhosts" for example (it doesn't matter as long as you know the name and it is different than "hosts"). This will retain your host file in the system incase you want to "rename" it back to host so the system can use it again in the event this does not solve your problem. If the system has created another "hosts" file when you have renamed it you would do the same thing rename that file to another name FIRST and then rename the one you had change the name of back to "hosts" (at which point your back to where you were originally in the event it made no difference and you would like to revert back to the way things were). By renaming the hosts file the system will ultimately create a new hosts file to use thus no problem with doing this but what it does is create the file from scratch thus if your original "hosts" file is "corrupted" then it could help solve the problem possibly.