Beta release of PicoScope 6 will work with Windows 98SE, ME, 2000, XP and Vista. Before installing the software please visit Microsoft Windows Update to make sure you have the latest service pack and critical updates for the version of Windows that you are running. (See specific requirements)

Picoscope 5 Operating System Requirements
Windows 98SE/ME MSI 2.0 and .NET framework 2.0
Windows 2000 Service Pack 3, MSI 3.0 and .NET framework 2.0
Windows XP Service Pack 2 and .NET framework 2.0

So version 5 for XP or 6 with Vista!

Graham