i had the exact same problem last saturday and i deleted all traces of NF from my computer ( also windows7).

As a last resort before smashing my keyboard i logged into windows under a different user account, in my case i logged in as guest, and dowloaded the game one last time and tataaa...it worked. after this my install on the admin user account started to work again too.

Not sure what the issue was, but it has been fine since.

Maybe give this a try

Glad ( or not so glad ) to see it is not just me having problems to redownload the latest NF version, on a windows 7 laptop that previously had NF installed and running.
The old version stopped running as I had not updated it for a long time ( old laptop ) So I tried to download and run the new version. Even did the manual patch. Now when I try to run Navyfield on the laptop the patch installer starts, I click 'ok' the screen goes blank and I am returned to the desktop with nothing happening.
It is quite frustrating seeing as it took just over an hour to download the file. 

Make sure in NF folders all files are deleted, even after uninstall.

c/program files/sd enternet/navyfield

Sorry if this is a bit basic, but not sure what u've tried, so here's one step off the list.

i had the exact same problem last saturday and i deleted all traces of NF from my computer ( also windows7).

As a last resort before smashing my keyboard i logged into windows under a different user account, in my case i logged in as guest, and dowloaded the game one last time and tataaa...it worked. after this my install on the admin user account started to work again too.

Not sure what the issue was, but it has been fine since.

Maybe give this a try