Many thanks to those who replied. I've joined the NTP list and some messages in the archive suggest that the NTP/Win 7 timekeeping problem has already been raised there. In the meantime I've adjusted the power-management and some device settings as suggested. In response to a question, the machine has 4GB or RAM and the worst-case load reported by Task Manager is about 65%.
>Also, the PlanePlotter website says that it runs on XP -- are you running something else that could load the system to the point where Win7 stutters?< I don't think so. PlanePlotter only seems to drive the system up to about 60-65% every now and then, presumably when it's downloading and uploading fixes. John _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.