virtualbox.org

hy,

i got issue to use my VM :
host: win 8.1
guest: ubuntu server 14
virtualBox v5

to be able to launch my virtual server i must :
-1- switch off the private network in the windows fire-wall
-2- switch on virtualBox
-3- launch my VM
-4- (optionaly) switch on the private network in the windows fire-wall

otherwise i can't launch my VM (even if all the virtualbox executables files are allow in the windows firewall)

Is someone know the right configuration for the windows firewall?

thanks,
and sorry for my poor english.