How to install 64bit binaries for TeX Live on Windows In the following, $INSTALLDIR is $SELFAUTOPARENT in TeX Live, that is, the parent directory of "texmf-dist". (1) Expand the file tl-win64.zip in $INSTALLDIR, (2) After expanding tl-win64.zip in $INSTALLDIR, change related command PATH from $INSTALLDIR\bin\win32 to $INSTALLDIR\bin\win64;$INSTALLDIR\bin\win32 Note that the following 32bit binaries in $INSTALLDIR\bin\win32 are still used on WOW64: jbig2.exe xindy-lisp.exe xindy.mem unzip.exe zip.exe gzip.exe gunzip.exe bitmap2eps.exe biber.exe dviout.exe psv.exe texdoctk.exe texworks.exe tlmgr-gui.exe. Moreover, tlmgr.bat does not exist in $INSTALLDIR\bin\win64 due to an obvious reason. Thus $INSTALLDIR\bin\win32 is necessary "after" $INSTALLDIR\bin\win64. If there are problems in 64bit binaries, it is easy to recover the original TeX Live win32, by changing back the PATH: $INSTALLDIR\bin\win64;$INSTALLDIR\bin\win32 ---> $INSTALLDIR\bin\win32 (3) Ghostscript is assumed to be 64bit. Therefore users should install 64bit Ghostscript and set the command PATH for the Ghostscript. However, don't define TEXLIVE_WINDOWS_EXTERNAL_GS in texmf.cnf, because the preinstalled 32bit Ghostscript is also used in several cases. The 64bit binaries are made with the latest sources. Therefore several TeX engines may not be compatible with the present TeX Live. Thus users should run the command fmtutil-sys --all -- Akira Kakuto