merging PDF files for free

download ghostscript.  run the following:
gswin32 -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=Merged.pdf -dBATCH 1.pdf 2.pdf 3.pdf

from:
https://www.cs.tcd.ie/Shane.OConchuir/Misc/MergingPDFs.html

don't vxupgrade /stand and /

Don't be a moron and do what I did: vxupgrade /stand and /

http://www11.itrc.hp.com/service/cki/docDisplay.do?docLocale=en&docId=ucr_na-KMN8606454124_ssb-1

Quoting:
On system using VxFS4.1 on HP-UX 11.23, the disk layout version
for "/" (root) and "/stand" may become unusable.

The commands vxupgrade and vxfsconvert in vxfs 4.1 and later have
the ability to upgrade the disk layout version of / and /stand
to dlv 6+.

The HP-UX bootloader cannot recognize the upgraded disk layout
and is unable to find a kernel to boot.