simply does not instal...

[rnervi]

version other than 2.2.0 simply does not instal anymore. Neither the new 3.0
setup process will starts, does 3 screen, and simply says "rolling back bye bye"
is there a log in which investigate ? some ideas ?
the current 2.2 is working fine, with all guests installed..

[Perryg]

This works about 95% of the time:

• Reinstall 2.2.0 (or what ever the version that you have now) and select repair. Once it has installed do not reboot. Run it again and tell it to uninstall.
  Then install the new version before you reboot.

Let me know if this does not work for you and I will send you information on how to totally remove it and then you can install the new version.

Edit: you should right click on the install icon and then left click on run as admin.

[rnervi]

good. and what about the installed machines ? I guess them are not lost, as are file based... perhaps the machine list get lost, but should have an "import" feature ?
I'll try suggested procedure after this assurance
Acting in safe way, I'm exporting all the machines via "export feature"...... who knows... backup done

setup actual (2.2.0) version and repair done.
2.2.0 setup -> remove - ok.
3.0 setup -> install

All ok !
machines are NOT lost and the new 3.0 is up and runnning !

thanks a lot