How to install 64bit binaries for TeX Live on Windows In the following, $INSTALLDIR is $SELFAUTOPARENT in the TeX Live, that is, the parent directory of "texmf-dist". Actually the directory $INSTALLDIR is shown by a command: kpsewhich --var-value=SELFAUTOPARENT (1) Expand the file tl-win64.zip in $INSTALLDIR. In the case of update, remove all files in $INSTALLDIR/bin/win64 before expanding tl-win64.zip, because it is possible that some files are deleted in a new tl-win64.zip. (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: gunzip.exe gzip.exe jbig2.exe latexindent.exe psviewer.exe tex2xindy.exe texindy.exe tlaunch.exe tlshell.exe unzip.exe xindy.exe xindy-lisp.exe xindy.mem zip.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. The dvisvgm.exe searches for gsdll64.dll by reading registry, and gsftopk.exe searches for gsdll64.dll in the command PATH. 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. From TeX Live 2020, the version of 64bit binaries will be synchronized with that of 32bit binaries. It is expected that common format files can be usable for 32bit/64bit binaries. -- Akira Kakuto