I'm reading in my program some files from system32 folder; and one of these files (C:\Windows\System32\gdi32.dll) demonstrates a very strange behavior. When I'm reading it from my program, it shows size of 310'784 bytes; and when I view it's size from Explorer, it shows size of 404'480 bytes. How could that be?
+3
A:
The most likely explanation is that your program is 32-bit and Explorer is 64-bit. When a 32-bit program opens files in C:\Windows\System32 (which contains 64-bit DLLs), it's actually redirected to C:\Windows\SysWOW64 (which contains 32-bit DLLs). The size difference you're seeing is the difference between the C:\Windows\SysWOW64\gdi32.dll and C:\Windows\System32\gdi32.dll files.
For more information, see KB article 896456.
Bradley Grainger
2010-06-23 06:07:42
Yeah, you're correct. However, my x32 file manager shows correct file size (the same as Explorer). How can it do that?
skevar7
2010-06-23 06:51:08
Perhaps it calls Wow64DisableWow64FsRedirection (http://msdn.microsoft.com/en-us/library/aa365743.aspx).
Bradley Grainger
2010-06-23 21:58:49