chm problems

This has nothing to do with .net ... but interesting.

Today I realized that no .chm file opened in my computer. It just tried to open the process and they closed without further clues.

Thanks to MJ's Help Diagnostics tool http://www.helpware.net/downloads/MJsDiag.zip
I found, under the HTML Help Run-time Components section this...

File not found: D:\WINDOWS\system32\hhctrl.ocx

I don´t know what the *** happened to this file, but after copying it again, it worked fine.