While installing Picasa on my newly installed OS on my machine i got this error " the current user is not allowed to install or update applications". after googling and spending sometime i got that its not actually picasa issue, its because of my OS and i tried a solution that worked for me.
1. Go to Server Manager >> Features >> Add Feature
2. Check Deskop Experiance and install it.
3. Reboot the system and its gone.