clear ur temp files/folders. reboot and try again...
use ccleaner to clean pc junk; if u dont have any other.
then revert pls.
also check if u meet the min requirements. here - *earth.google.com/support/bin/answer.py?answer=20701
else u can always post in the google earth forum at *bbs.keyhole.com/ubb/postlist.php/Cat/0/Board/SupportGEFree/page/0