OK you forced be to retry. I fired up an old win XP system.
Alt + Prnt screen then opend paint and did a paste - walla, there was a pitcure of an opened window (CPU-z).
Cntr + print Screen, then paste into Paint and walla entire disktop.
Note: I just finished reloading XP on this system last week. It's an old computer that I use to clone SCSI HDDs that have windows 3.11 on them. I have never had a problem with Win XP on any of the computers that I've used, and that is a GOOD number of.
On sending with email:
.. As WR2 stated if using Galdwin program, or
.. If using windows Print screen. Paste into paint (or other program) and save, then send as an attachment.
@ Hawkeye22 LOL, Your right, do not need the ctrl for the whole desktop - works ether way (just tried).