在64位系统下的32位程序/DLL眼中的System32目录

由于需要把一个老VB6程序升级到VB.NET，于是就先用VS2008升级，结果升级过程中说缺少CdoNts.dll，于是从Windows Server 2003中copy一份到本地System32目录下，并注册，结果提示“The module CdoNts.dll failed to load. The specific module could not be found.”。傻眼了，该不是我64位Windows的原因吧？后来Google一番发现，果然如此，原话摘录如下：

If your DLLs are 32-bit, you need to explicitly call the 32-bit DLL
regsvr32. It is located in %windir%\syswow64.

The problem is that 32-bit and 64-bit programs have a different view of the
file system and "system32" is not the same to them. 32-bit programs see
%windir%\syswow64 as "%windir%\system32". 64-bit programs see the real
system32, which is for 64-bit programs and dlls.

 简而言之，在32位程序的眼中，他们眼中的System32目录，在64位系统中其物理路径其实是SysWow64目录，而真正的System32目录下都是64位的东西…… 这真够让人纠结的，没办法，为了兼容性。呵呵。

把CdoNts.dll拷贝到SysWow64目录下，然后注册就可以了。