The Old New Thing
Practical development throughout the evolution of Windows.
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ReadDirectoryChangesW to know when someone is copying a file out of the directory?" />
Apr 3, 2026
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How can I use ReadDirectoryChangesW to know when someone is copying a file out of the directory?
File copying is not a fundamental operation, nor is it even detectable at the file system layer.
WM_
Apr 2, 2026
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Why doesn’t the system let you declare your own messages to have the same semantics as WM_COPYDATA ?
Tempting but misleading.
C++: The Programming Language raises questions not answered by the cover" />
Apr 1, 2026
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The cover of C++: The Programming Language raises questions not answered by the cover
What are we reading about here?
Mar 31, 2026
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Before you check if an update caused your problem, check that it wasn’t a problem before the update
It was going to be like that when I got here.
Mar 30, 2026
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A question about the maximimum number of values in a registry key raises questions about the question
Why is this even a question?
Mar 27, 2026
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What if a dialog wants to intercept its own message loop?
You can steal them from your owner.
WM_MessageBox?" />
Mar 26, 2026
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Why doesn’t WM_ENTERIDLE work if the dialog box is a MessageBox?
Because it opted out.
MsgWaitForMultipleObjects instead of GetMessage?" />
Mar 25, 2026
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How can I change a dialog box’s message loop to do a MsgWaitForMultipleObjects instead of GetMessage?
The dialog box lets you change how it waits.
Mar 24, 2026
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Windows 95 defenses against installers that overwrite a file with an older version
A very primitive version of recovery.