system
1
Do I have to type my licence key everytime i open avast for use?
while running adaware, or after inactivity, I often got these messages before my first scan with avast:
“trjojan horse downloader found in system volume info(long adress)
keenval.o or keenval.p
or
dyfica
or
tooncom
please run avg for windows”, but avg didn’t find it
i runned avast and it found some viruses and i seem clean for infections now 
my avg is uinstalled
Eddy
2
Do I have to type my licence key everytime i open avast for use?
No, once is enough. If you have HOME, you will need to get a new key every 14 months. If you have PRO, you will need to get a new key if the period you payd for expires.
found in system volume...
Disable system restore, reboot and see if the problem is solved.