The Old New Thing

What is the strange garbage-looking string in the "command" value of a static verb?

July 31, 2014 Jul 31, 2014 07/31/14

Raymond Chen

A customer from a major software vendor asked, "What is the significance of the command value that can be found under HKCR\⟨progid⟩\shell\open\command. It appears to be a copy of the default value, but with the program name replaced with apparent garbage. We've seen this both with Microsoft products as well as products by other ...

If you want to be notified when your app is uninstalled, you can do that from your uninstaller

July 30, 2014 Jul 30, 2014 07/30/14

Raymond Chen

A customer had a rather strange request. "Is there a way to be notified when the user uninstalls any program from Programs and Features (formerly known as Add and Remove Programs)?" They didn't explain what they wanted to do this for, and we immediately got suspicious. It sounds like the customer is trying to do something user-hostile, like ...

Finding the shortest path to the ground while avoiding obstacles

July 28, 2014 Jul 28, 2014 07/28/14

Raymond Chen

Today's Little Program solves the following problem: Consider a two-dimensional board, tall and narrow. Into the board are nailed a number of horizontal obstacles. Place a water faucet at the top of the board and turn it on. The water will dribble down, and when it hits an obstacle, some of the water will go left and some will go right. The...

How do I obtain the computer manufacturer's name from C++?

July 25, 2014 Jul 25, 2014 07/25/14

Raymond Chen

Some time ago, I gave a scripting solution to the problem of obtaining the computer manufacturer and model. But what if you want to do this from C++? I could translate the script into C++, or I could just point you to Creating a WMI Application Using C++ in MSDN. In particular, one of the WMI C++ Sample Applications does exactly what you ...

When I send a WM_GETFONT message to a window, why don't I get a font?

July 24, 2014 Jul 24, 2014 07/24/14

Raymond Chen

A customer reported that the WM_GET­FONT message was not working. Specifically, they sent the message to a window, and they can plainly see that the window is rendering with a particular font, yet the WM_GET­FONT message returns 0. Why isn't the window returning the correct font handle? The WM_SET­FONT and WM_GET­FONT messages...

When will GetSystemWindowsDirectory return something different from GetWindowsDirectory?

July 23, 2014 Jul 23, 2014 07/23/14

Raymond Chen

Most of the time, the Get­Window­Directory returns the Windows directory. However, as noted in the documentation for Get­System­Windows­Directory: With Terminal Services, the Get­System­Windows­Directory function retrieves the path of the system Windows directory, while the Get­Windows­Directory ...

How can I get the URL to the Web page the clipboard was copied from?

July 21, 2014 Jul 21, 2014 07/21/14

Raymond Chen

When you copy content from a Web page to the clipboard and then paste it into OneNote, OneNote pastes the content but also annotates it "Pasted from ...". How does OneNote know where the content was copied from? As noted in the documentation for the HTML clipboard format, Web browsers can provide an optional Source­URL property to ...