[SOLVED] Error writing to file .css.js installing Zimbra Desktop 7.3 on Windows 10 and 7 64-bit

[NA_smh]

I've tried to install Zimbra Desktop 7.3.0 on two brand new PC, one with WIN7 64-bit Professional and the other with WIN10 Professional 64-bit and I get always the same error while the installer is copying the files: "Error writing to file: C:\Program Files\Zimbra\Zimbra Desktop\jetty\webapps\zimbra\skins\twilight\img\images.css.js. Verify that you have access to that directory."
The account is administrator and the msi file has been executed with administrator rights.
The JRE for 64-bit OS is already installed.

Anyone has any suggestion?

[NA_smh]

sorry, it was my stupid antivirus...