I have WinXP Pro SP3 and my Google Earth installation says version 5.1.3533.1731 . When I check Help/Check Updates Online within GE it says that no update is available.
However, Wikipedia reports that the latest final version is 5.1.7894.7252 as shown here:
http://en.wikipedia.org/wiki/Google_earth
So I uninstalled my GE and reinstalled it using both the official Google earth site and this site:
http://www.softpedia.com/get/Others/Home-Education/Google-Earth.shtml
However, after "updating" GE as explained before, my GE installation (Help/About) still reports version 5.1.3533.1731
Anyone was able to update to version 5.1.7894.7252?? I don't know why my GE still shows the old version even after updating. Thanks.