Can't use beamer package on Windows because 'translator.sty' is missing

In Windows goto All Programs the Miktex 2.9 then Maintenance(admin) then Miktex Packet Manager(Admin). Select beamer under column name . Then select + on the top left. Select translator under column name . Then select + on the top left.

Converting Ulrike Fischers comment into a CW answer:

Something blocks a file from the package. Close everything (e.g. pdf-viewer with open documentation). Then start the package manager, synchronize (menu repositories) and try to install the package from there.