Thank You for Your answer.
I checked user credentials couple of times, but unfortunately this not solved my problem - even if I changed user password and prepare VM again.
The user has administrator rights. Guest Agent is starting automatically. VM has access to the network and is visible from host machine. Snapshot was created after VM was shut down.
One more thing. This VM machine is not a member of any domain. So maybe this is a reason?
After installation, GA asking for user name, password and domain. What I should type in domain field if machine is not a member of domain? Leave it blank? Type computer name?
Right now we are using evaluation version of AdminStudio, so this might be another reason - I doubt it, but anything is possible ;-).
Once again, thank You for Your help.
Regards
Mateusz