The principle of prevention of several instances have been reversed now.
On all WinXP variants a small file "preventdouble.ea" will be installed where the exe file of analysis resides. If users try to start EpiData Analysis twice a warning will be issued telling that analysis is already running.
The reason for this is that during teaching I have often experienced beginners not being able to find their work since they started maybe three or four simultaneous copies of analysis by double clicking on the start icon and not noticing the other running copies.
Experienced users can block this mechanism by simply deleting the file.
On Win9x (95 98, me etc) the file is NOT installed since on some PC's they were blocked when the control mechanism was started. Users can experiment with manual creation of an empty file with the same name.
Only one other difference in behaviour is known : To run a command prompt from within analysis two commands exist: dos // which works on all pc's ! // which only works on XP+ variants of windows.
regards
Jens Lauritsen EpiData Association