I have V126.96.36.199 installed on both an old 2Core 3GHz HP DC5700 32bit XP Pro machine with 3.5GB memory and on an I7 4/8 Core with 16GB memory. The Scope is a 4262 from April 2012 (Calibration date in "About" dialog).
On the old XP machine, Picoscope runs reliably and continuously though at high processor loading, as it has done with previous versions.
On Windows 8.1, the main Picoscope window randomly freezes in a few seconds to 10's of seconds. with no trace updates and usually it is unresponsive to mouse movements and menu clicks. The PicoScope app is still running and painting the window as overlaying it and exposing again paints correctly.
If you unplug the USB cable the "check USB appears". Restoring the cable restores the application to life for another indeterminate time.
The only unusual thing about the Win8.1 machine is that it has VMWare Workstation V10 installed and running. Closing the VMWare application does not change the Picoscope problem, but other VMWare components would still be running
I have uninstalled the version of Picoscope, deleted the Appdata\Local\Picoscope folder and re-installed with Run as Administrator. This made no difference.
I do not see any recent similar problems on the forum.
I can continue to use the XP machine but was hoping to move to the faster machine.