Gimp Windows Installer failure

Hello,

I just wanted to install Gimp on my computer for the first time.
I tried 2.4.6, 2.4.5 and 2.2.17.
In all cases I got the same installer message:
"Internal error: failed to get version numbers of _shfoldr.dll."
I could not find a DLL with this name on my system.
Any hints for me what to do?

Thanks.
Jan