1) I deleted Evernote installation folder, and every file with Evernote in the name;
2) CCleaner to clean registry;
3) Manual clean on registry searching for Evernote
Until there, I could launch the installer but got an error about just one user installation allowed...
Then, I did what this post recommended: http://discussion.evernote.com/topic/22282-%E2%9C%94-latest-evernote-cant-be-installed-after-old-version-not-uninstalled-properly/page-10#entry125311
It worked fine... Finally I have my beloved notes with me, again... :-)
P.S. The folder where I found the log file was c:\users\alexgv\appdata\local\Temp, where alexgv is my user on Windows 7.