I regularily test Ping Plotter on a Windows XP system - and have heard from quite a few people that have had great success with Ping Plotter on XP. We definitely support running Ping Plotter on the Windows XP operating system.<br><br>I'm currently running a trace that has been running on a Windows XP system continuously since early November - and there are 1.9 million samples in memory (it's getting a bit unweildy at 1.9 million samples, I must admit, but it's still running!).<br><br>If you see anything abnormal with Ping Plotter under XP, please let us know.<br><br>Best wishes - and happy holidays!<br><br>