i am running on xp
have tried going into regedit, hikey_current, ect but seems ok
what do i do now
Not sure if you have tried this.
sounds like you know how to use regedit. make a back up of the registry incase you screw up (warning deleting the wrong thing from the registry can corupt your computer requiring you to reinstall windows from scratch)
delete any reg entries that are associated with google earth.
reboot the computer
download the google earth again make sure you rename the file to somthing other than the defult name and also save in differnt location of hard drive.
not sure if it will work but thats what i would do. a starting point.
(quick google search on the issue people saying its associated with a corupt download)