[Tex/LaTex] Can’t use beamer package on Windows because ‘translator.sty’ is missing

beamermiktex

I am trying to compile a presentation with beamer on Windows. However, even the most simple example presentation aborts. Instead, I am told:

starting package maintenance...
installation directory: C:\Users\admin\AppData\Roaming\MiKTeX\2.9
package repository: http://mirror.physik-pool.tu-berlin.de/tex-archive/systems/win32/miktex/tm/packages/
lightweight database digest: 3a990fd9300abc5d0d8c99b2064abddb
going to download 2628706 bytes
going to install 346 file(s) (1 package(s))
downloading http://mirror.physik-pool.tu-berlin.de/tex-archive/systems/win32        /miktex/tm/packages/beamer.tar.lzma...
2628706 bytes, 282.04 KB/Sec
extracting files from beamer.tar.lzma...

Unfortunately, the package beamer could not be installed.Please check the log file:
C:/Users/admin/AppData/Local/MiKTeX/2.9/miktex/log/pdflatex.log
======================================================================

The log file says:

2017-05-24 13:40:57,040+0200 FATAL pdflatex - Info: path="C:\Users\admin\AppData\Roaming\MiKTeX\2.9\tex/latex/beamer/beamer.cls"
2017-05-24 13:40:57,040+0200 FATAL pdflatex - Source: Libraries\MiKTeX\Core\File\win\winFile.cpp
2017-05-24 13:40:57,040+0200 FATAL pdflatex - Line: 286
2017-05-24 13:41:44,697+0200 INFO  pdflatex - installing package beamer triggered by tex\latex\beamer\translator\translator.sty
2017-05-24 13:41:48,400+0200 INFO  pdflatex - mpm: starting package maintenance...
2017-05-24 13:41:48,400+0200 INFO  pdflatex - mpm: installation directory: C:\Users\admin\AppData\Roaming\MiKTeX\2.9
2017-05-24 13:41:48,400+0200 INFO  pdflatex - mpm: package repository: ftp://ftp.tu-chemnitz.de/pub/tex/systems/win32/miktex/tm/packages/
2017-05-24 13:41:48,633+0200 INFO  pdflatex - mpm: lightweight database digest: 3a990fd9300abc5d0d8c99b2064abddb
2017-05-24 13:41:48,649+0200 INFO  pdflatex - mpm: going to download 2628706 bytes
2017-05-24 13:41:48,649+0200 INFO  pdflatex - mpm: going to install 346 file(s) (1 package(s))
2017-05-24 13:41:48,655+0200 INFO  pdflatex - mpm: downloading ftp://ftp.tu-chemnitz.de/pub/tex/systems/win32/miktex/tm/packages/beamer.tar.lzma...
2017-05-24 13:41:57,484+0200 INFO  pdflatex - mpm: 2628706 bytes, 290.95 KB/Sec
2017-05-24 13:41:57,504+0200 INFO  pdflatex - mpm: extracting files from beamer.tar.lzma...
2017-05-24 13:41:58,245+0200 FATAL pdflatex - Windows API error 32: The process cannot access the file because it is being used by another process.

2017-05-24 13:41:58,245+0200 FATAL pdflatex - Info: path="C:\Users\admin\AppData\Roaming\MiKTeX\2.9\tex/latex/beamer/beamer.cls"
2017-05-24 13:41:58,245+0200 FATAL pdflatex - Source: Libraries\MiKTeX\Core\File\win\winFile.cpp
2017-05-24 13:41:58,245+0200 FATAL pdflatex - Line: 286

What exactly is happening here and how can I use the beamer package on Windows?

Best Answer

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.