The easiest way to install Lyx on Windows is to use the LyxWinInstaller, which installs Lyx together with the software it needs, including performing a basic install of Miktex.
If Lyx still doesn't find Miktex after installation, which I have heard can happen if it is installed separately, check that the Windows system variable miktexdir is set to the path of the Miktex program directory.
(this is mostly from memory; i can't find most of the references in print or on line, although i know they exist somewhere.)
tex, as a system created in the u.s., was based on lettersize paper -- 8.5in x 11in.
in the original tex setup, now ensconced in plain.tex, the page size settings are
\hsize=6.5in and \vsize=8.9in, which results in 1 inch margins (exact horizontally, and very close vertically) when a full page is centered.
in the early days, there was also a need to set a default location for the upper-left-hand corner of a page when it was to be printed. either at an early tug meeting at stanford, or perhaps in a discussion within the tex project group, it became clear that this would be arbitrary (although required). david fuchs (who was writing a key output device driver) stated, by fiat, that the origin would be set at 1 inch down, and 1 inch from the left edge of the paper. with no overwhelming objections, that became the default.
i can't prove it, but my guess is that latex simply followed the lead of tex itself in using this setting.
Best Answer
As Alexander Grahn suggested - instead of using
dvipdfyou could do it in two steps:Run
dvipswith the desired paper option, such asRun
ps2pdfwith the desired paper option, it takes the same asgsaka ghostscript, such asI recommend using pdfLaTeX for directly producing PDF without those conversions, it has further benefits for example its microtypographic capabilities.