On our particular setup (Windows 7 Ultimate 64-bit), the ScreenSlider icon appeared in the system tray, but it didn't do anything when we left- or right-clicked it. We haven't seen other users complain about this issue, so that may have been an isolated incident. In any case, running ScreenSlider from its Start menu shortcut opens its menu just fine.

After opening the ScreenSlider PC menu, click the Find Devices link at the top. A dialog box will open, and the app will scan your network for the tablet. If the tablet and PC are on the same network and subnet, and if the ScreenSlider app is running on the tablet, after a few moments the tablet should appear in the list of available devices, with its IP address and the name you entered in step two.

Double-click your tablet's entry in the list of devices; a window should pop up on the tablet's screen with a unique PIN. You need to enter that PIN into the connection window on the PC. Once you have done that, click OK, and the tablet should begin acting as a secondary display in extended desktop mode.