Dear Satyabrat,

The behaviour of the property inspector you describe normally happens when people switch from a situation with an external monitor connected to their laptop to using the laptop screen.
USoft stores the position of the Property inspector dialog in the Windows registry. In some cases this position is off the screen, outside the display area. As a result it seems like the Property inspector is not opening.

The solution is to remove or alter the key:

"HKEY_CURRENT_USER\SOFTWARE\USoft\USoft Developer\Designer\Designer\PropertyInspector".
If you remove it, the Property inspector will open at a default position the next time you open the Windows Designer. Restarting the Windows Designer will also recreate the key mentioned above.

Regards,

Robert