Having the Shadow Copy service on Windows Home Server enables you to recover files that have been changed or deleted. As James Tenniswood states:
This can be really worth while if youâ??ve ever been caught accidentally saving over a document or erasing a folder, as you can look thought the folder at in any of itâ??s saved states and either restore or copy the contents to a safe place.
James shows you how to enable the Shadow Copy service and change its default settings, which you can view here.