Convert .oxps file to .pdf file on Windows 8

This is how I would do it:

1. Download CutePDF writer
2. Set the writer as your default printer (you can change it back later)
3. Place all your .doc files in the same folder
4. Highlight all the files, right-click, Print

Only downside is that you have to click Ok once for each file.

Typically, .prn is the suggested file extension on Windows when you use the "print to file" option in any program that can print its content. Which printer driver is used to generate the .prn file depends on the printer you selected when printing (or on your default printer).

Typically, the real content behind that .prn extension may therefore vary as wildly as there are printer driver types available: PostScript (Levels 1, 2, 3), PCL (half a dozen types), ESC/P, ESC/P2, HP/GL, Prescribe, RPCS,.... you name it.

If your *.prn really is a PostScript, you can easily convert it with Ghostscript (or Acrobat Distiller) to PDF.

If your *.prn really is a PCL, you can also convert it, using another program from out of the Ghostscript stable, named GhostPCL.

Here are two example commandlines:

gswin32c.exe ^
    -dBATCH ^
    -dNOPAUSE ^
    -sDEVICE=pdfwrite ^
    -sOutputFile=output.pdf ^
    [...more Ghostscript CLI options as needed...] ^
    c:/path/to/input-which-is-postscript.prn

pspcl6.exe ^
    -dBATCH ^
    -dNOPAUSE ^
    -sDEVICE=pdfwrite ^
    -sOutputFile=output.pdf ^
    [...more Ghostscript CLI options as needed...] ^
    c:/path/to/input-which-is-pcl.prn

For downloading GhostPCL, see here: https://www.ghostscript.com/download/gpcldnld.html.