AVGUI not reacting

Hello,

I installed AVG2015, but I do not have its icon in the system-tray and I cannot start AVGUI from command line. If I try with "avgui" from prompt, simply I do not get any reaction. No errors in the command prompt and GUI is not showing up (same if I double-click on the icon on the desktop).
Tried to uninstall and re-install several times (uninstalling using windows control panel, AVG remover, or Revo uninstaller). No results.
AVG processes seems running and working.
I also tried to scan the system in windows safe-mode and here the GUI works, but no viruses were found.
Any ideas?

Hello Alberto
If the problem still persists then please download AVG BFE Fix tool. and follow the steps described here
| AVG (https://support.avg.com/SupportArticleView?l=en_US&urlname=Code-0xC0070643-or-0xC007001C-when-installing-AVG)

Check conflict applications. If you use another antivirus to remove it
Thanks

No results, after several uninstall and reinstall.
Tried to do an installation repair... Got this error at the very end, after several minutes of waiting time!
Error code: 0xC0070643
Error while starting up watchdog service (0xC0070426) - translated from italian

I have really no ideas now.

Hello Alberto
If the problem still persists then please download AVG BFE Fix tool. and follow the steps described here
| AVG (https://support.avg.com/SupportArticleView?l=en_US&urlname=Code-0xC0070643-or-0xC007001C-when-installing-AVG)

Check conflict applications. If you use another antivirus to remove it
Thanks

No results, after several uninstall and reinstall.
Tried to do an installation repair... Got this error at the very end, after several minutes of waiting time!
Error code: 0xC0070643
Error while starting up watchdog service (0xC0070426) - translated from italian

I have really no ideas now.