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You can use an OVERLAPPED structure with synchronous I/O, too
Even if you didn't open a file with FILE_FLAG_OVERLAPPED, you can still use the OVERLAPPED structure when you issue reads and writes. Mind you, the I/O will still complete synchronously, but you can...
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Registration-free COM the old-fashioned way: The car mp3 player
Windows XP introduced Registration-Free COM, permitting you to place your COM object registrations in a manifest rather than in the registry. Very handy when you want to support xcopy deployment or...
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There's the interface contract, and there are the implementations of the...
Ivo wants to know whether it is legal to use NULL as the icon parameters to IExtractIcon::Extract. The documentation says that the parameters are optional, but some shell folder implementations treat...
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Microspeak: scoped to
The Merriam-Webster dictionary gives as the meaning of scope as a verb to look at for evaluation, as in "to scope out the competition." But that's not how we use it at Microsoft. Here are some fake...
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I know that an overlapped file handle requires an lpOverlapped, but why does...
A customer observed that the formal requirements for the ReadFile function specify that if the handle was opened with FILE_FLAG_OVERLAPPED, then the lpOverlapped parameter is mandatory. But the...
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What is the real maximum length of a DNS name?
The maximum length of a DNS name is 255 octets. This is spelled out in RFC 1035 section 2.3.4. A customer didn't understand why the DnsValidateName was rejecting the following string: (63 letters).(63...
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You already know the answer since you do it yourself
A customer was writing a program that performed virtual drag/drop. They were using the IStream technique but found that many applications don't support drag/drop of virtual content. They support only...
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Why do we need IsDialogMessage at all?
alv wonders why we need the IsDialogMessage function at all. "All its activity could take place inside the window procedure of the modeless dialog itself", since when it doesn't have focus, it...
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There's the kernel, and there's kernel mode - confusing historical terminology
A few weeks ago, I mentioned that the kernel folks decided not to expose bonus bytes to applications. Some people were confused by this statement, not for what it said, but for what it implied. "Wait,...
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Why doesn't the Version tab show up for very large files?
If you have a really large file and try to view its properties in Explorer, you may find that the Version tab doesn't appear. What's going on? The Version tab uses the GetFileVersionInfo family of...
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Why don't I get a Caps Lock warning balloon any more?
A customer asked for help diagnosing a problem they were experiencing on Windows XP: My customer reports that on their machines, they do not get the warning balloon that appears when Caps Lock is set...
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What does INIT_ONCE_CTX_RESERVED_BITS mean?
Windows Vista adds the One-Time Initialization family of functions which address a common coding pattern: I want a specific chunk of code to run exactly once, even in the face of multiple calls from...
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Why are programs allowed to use normal characters as hotkeys?
alv wonders why programs are allowed to create hotkeys for normal characters. The example given is the famous AltGr modifier, equivalent to Ctrl+Alt. Programs which ignore the guidance and use...
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I thought I was so clever, salvaging an old floppy drive from a dead...
When one of the oldest computers at Microsoft still doing useful work finally died, I had the presence of mind to salvage the 5¼″ floppy drive from the machine, so that I could (someday) extract the...
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How do I prevent users from opening TIF files?
A customer had a question about their Windows XP installations. (This question was from several years ago, so the fine details aren't really relevant any more, but I'm actually telling this story for...
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Shortcut properties are in the shortcut, so if they can read the shortcut,...
A customer wanted to know if "there was a way to hide the properties of a shortcut." We asked for an explanation of the problem they were trying to solve, so we could understand what their question...
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A process shutdown puzzle, Episode 2
A customer reported that their program would very sporadically crash in the function CloseThreadpoolCleanupGroupMembers. The customer was kind enough to provide a stack trace at the point of the...
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What were the tests that WinG did to evaluate video cards?
Georg Rottensteiner was curious about the weird things that WinG performed on installation to evaluate video cards. "What did it do actually and what for?" I don't actually know, since I was not...
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When you don't speak a language, don't sound like you speak the language
I appreciate the help from Christoph and Voo in refining my German. But that reminds me of a story about a friend of a friend. She was in Japan to visit some friends. Although she speaks English and...
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What happened to the Summary information created on Windows 2000 and Windows XP?
In Windows 2000 and Windows XP, you could add Summary information on the Details property page to files of all types. Text files, image files, some crazy file your grandmother sent you in a file...
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