Simple, useful and just plain fun to play around with, this Windows spy weighs in at an incredible 17kb
WinSpy++ can obtain the following window properties:
Window Class and Name.
Window procedure address.
All window styles and extended styles.
Window properties (set using the SetProp API call).
Complete Child and Sibling window relationships.
Scrollbar positional information.
Full window Class information.
New in version 1.5!
Retrieve passwords from password-edit controls!
Edit window styles!
Alter window captions!
Show / Hide / Enable / Disable / Adjust any window in the system!
Massively improved user-interface!
View the complete system window hierarchy!