i think this windows one works but i'm not sure. it's not very good.
Don't unarchive Amiga software on Windows. Extracting the Amiga files on to a Windows filesystem fscks with the file attributes of the files within the archive, which is probably why your copy of IDEfix isn't working properly. Instead, get a proper dearchiver working on the Amiga, copy the .lha file to the Amiga, and unarchive it there.