Hi, I'm running xubuntu 12.04 and trying to install MS office home and student 2007. I used playonlinux to try and install it and I got this error message "z:\media\OFFICE12\HomeStudentr.WW\OSETUP.DLL digital signature does not validate or is not present" any idea what this means or how I fix it? I don't know if its my DVD or not but last week I was able to install this onto another computer running windows no problem.