From the download page, I start download of yEd-3.10.2_with_JRE_setup.exe. I am saving the file to MyUserName\Downloads (i e, C:\Users\MyUserName\Downloads). The browser shows the progress of the 53 MB download, and during the donwload, 2 files appear in the download directory: yEd-3.10.2_with_JRE_setup.exe and yEd-3.10.2_with_JRE_setup.exe.PART. The latter increases in size, matching the browser's download progress in size.
The instant the download completes, and without any further action on my part, both files vanish from the download directory. They are nowhere on the C:\ drive, nor in the recycle bin.
How do I get the installation to work? Prior to this installation attempt, I sucessfully ran yEd using the web interface. JRE was already installed on my machine.
Windows 7, 64-bit. Firefox 19.0.2. Java Standard Edition v7 update 15.