Spyware Blaster

Does Spyware Blaster snap shot act as a volume shadow copy? Is there any freeware for a volume shadow copy? Can a Volume shadow copy help me in case of a registry error?

Short answer is no it is very limited as the description in SpywareBlaster states, see image.

I think the volume shadow copy is considerably more than that, http://technet.microsoft.com/en-us/library/cc785914(WS.10).aspx.