SHLoadNonloadedIconOverlayIdentifiers doesn't work in the WinXP?

Question

In the current project, I'm making an icon overlay. The actual implementation is completed.

And I made sure that it worked well in WindowsXP and Windows7.

But I want to appear to overlay icon immediately without restarting the explorer process.

So I found a way that SHLoadNonloadedIconOverlayIdentifiers function signals the shell and then load the nonloaded Shell Extension dll.

I make sure in the MSDN that minimum supported clinet of this function is Windows 2000 Professional.

In Windows7, this function worked fine, but it did not work in WindowsXP.

I would like to know why.