There's just way too many tracking cookies out there. For the most part, they aren't seriously malicious. SpywareBlaster does block quite a few, but as cheesecheeks said, it's main goal is blocking malicious ActiveX controls from being installed. It does this quietly, in the background, without using system resources.
Cookies get placed on your machine from nearly every site you go to.
Cookies are nothing to be worried about. They get installed on your computer everytime you visit any webpage. Now some of those are good cookies that get installed for ease of use for next time you visit the same page, but some cookies are spyware used for tracking users surfing habits.
Most of those cookies are third party cookies that can be blocked:
go to Tools
Click the small triangle next to cookies to expand that tab and put a check next to "for the originating website only
". This will prevent third party cookies from being installed on your computer.
go to Tools
> Internet Options
and click on Advanced
in the Privacy tab
Now put a check next to "Override automatic cookie handling
Set first party cookies
and third party cookies
Also put a check to "Always allow session cookies
your way out.
This won't prevent all bad cookies from being installed, but will reduce the amount.
From the official SpywareBlaster
SpywareBlaster is a preventative program. It sets flags in the registry to prevent the running of a specific list of bad spyware related ActiveX controls. This includes general spyware and malicious dialers. It also blocks a list of known spyware related cookies in IE6. SpywareBlaster should be run periodically, say once a week, to check for updates to its database. Other than that it doesn't need to be running to provide protection, so there are no processes run either at startup or in the background.
MRU is Most Recently Used lists of programs/files, etc....used by Windows.
Most Recently Used (MRU) is a term used in computing to refer to the list of programs or documents which were last accessed. It can be of convenience since it allows you to quickly see and access the last few used files and documents. But could also be considered bad in terms of privacy.
All is well. Remain calm.