GetWindowText is a tiny (64KB!) tool that helps you read the text in informational dialog windows. It is written by Nenad Hrg from Germany, who has written several useful Windows tools like this.
First, download, unzip and run the tool. Left-click and hold down on the tool's icon shown in its window. Your cursor will change to
*****. Keeping the button pressed, drag the cursor to any window text you want to grab. That text will appear in the text box of the tool.
Tried with: GetWindowText