I bought an older version of this software from a friend and the Rosetta Stone support hasn't been of much use. When installing, at the end of the process I get an error from the installer that says something along the lines of:

Error 1330. A file that is required cannot be installed because the cabinet file [file.cab] has an invalid digital signature.

This isn't the first time I've had such an error, some time ago I was unable to install a game I bought because of the same thing. I extracted the cab file itself just to see what it was and it's just an archive of icons and things like that, so it's not even like I'm missing out on much :/ Any advice/tips on how to work around this error would be appreciated e.g. if it's possible to make the installer ignore digital signatures.

Running Windows 7.