I prefer buying laptops directly from Microsoft store / Apple store because they are having clean OS install (no freeware from 3rd parties). If you happen to buy Microsoft OS based laptops from OEM / retailers then the following tools will be of useful to you.
PC Decrapifier – It will help lists the unwanted programs and help to remove them – http://www.pcdecrapifier.com/home
Unlocker – It will help to uninstall program which may be holding an unexpected file lock / some kind of odd access restrictions – http://www.emptyloop.com/unlocker/
Recuva – Oops! moment helper – recovering deleted files – http://www.piriform.com/recuva