The latest version of LaTeX for v4.2 is dated December 2001.
If you already have this version you can ignore errors about LaTeX being out-of-date. Simply press the Proceed Button and ignore the error message at the end of typesetting. Your LaTeX format file will have been created and is usable without further warning messages.
Otherwise download (http://www2.pctex.com/ftp/ltx0112.exe) the basic LaTeX distribution (1.1MB).
This download will copy the LaTeX files into your PCTeX folder. To complete the installation, you must initialize a new format file. To do this, start PCTeX and choose Typeset..INITeX. In the INITeX window, choose LaTeX.
In the "Path to input files" box, enter <path>\LATEX, where <path> is the location of your PCTeXv4 installation -- on our system <path> is C:\PCTeXv4, and the entry in the "Path to input files" box is C:\PCTeXv4\LATEX.
Click the INITeX button and the format file will be created. The next time you typeset a LaTeX document the latest LaTeX version will be used.
To install Babel (for multiple language usage) install the above LaTeX download and then download (http://www2.pctex.com/ftp/lbab0112.exe) the additional Babel files (2.0MB).
To complete the installation of Babel, do the following:
(Technical note: the basic LaTeX files include the LaTeX macros and the packages AMSLaTeX, Cyrillic, Graphics and Tools. The full LaTeX distribution includes all of the LaTeX systems, though many of these are not installed. The various systems are in folders within the LATEX folder and the documentation and complete sources are included. You are welcome to explore these systems; however, our technical support staff will not be able assist you installing and working with them.)