@skawo96: start, run, services.msc, right click "Error reporting service", properties, general tab, "startup type: Disabled". As normal from then on.
Back on topic there are two categories. Shell replacements running on top of explorer often using explorer as a backend or file browser and actual replacements.
They are also used for two main reasons: actual customisation and locking down a machine.
Actual replacements are usually paid software while things that look fancy are free, I will mention that there are a lot of extensions to explorer and tweaking software/options that can replicate most if not all of the features.
Then there are two types expansions on the explorer concept and actual changes.
litestep has about 20 differing versions/clones and none have proven to be worth my time yet, others quite like them so do what you will. http://www.lsdev.org/doku.php
For the record most of these are fallback and for when I am doing risky stuff without a throwaway wine or virtual machine or want to fix stuff without rebooting. A heavily customised version with a few extras is what I usually use, consult this thread for more on that: http://gbatemp.net/index.php?showtopic=71377