Hey David,
Thanks for sending over this info - we appreciate it.
The culprit here is *most likely* the number of targets you trying to load up. With any 3x version of PingPlotter, the program works great up to around 50 total targets (we've had some users push this up to 100 in the past, though). With 195 targets, you're likely going to run out of window handles (or a related resource), which can result in errors like the one you're seeing here. Different operating systems can have different per-process resource limits, which may explain why it worked on 2003, and not on 2012.
We aren't experts on this (because we really only support this version of PingPlotter up to 50 targets) - but you could look into increasing the limit on window handles for this machine - which may help get you closer to what you're after.
We recently released PingPlotter v4 as well - in which we specifically addressed the number of targets PingPlotter can handle (we test to 250 targets). We do this by *not* creating tabs for every running target. This is a paid upgrade from PingPlotter v3, and if you're interested, you can see more information here:
http://www.pingplotter.com/whats-in-v4.htmlIf you have any questions, or if there's anything else we can do to help out - please let us know!
Best wishes,
-Gary