Thanks for posting! I have a feeling that the problem, based on this post and the one about ITA not creating directories, has to do with the account you used to install IT Assistant. If you use the Administrator account, or a service account created as a copy of that account, then it would probably have the permissions to create the directory and issue restart commands to your systems. Maybe try installing another instance of ITA with the Administrator account, set up one server to be discovered, discover it, and try to push updates to it?
If that doesn't change anything, then I suggest looking at your Global Policies or other security settings to see if something there is preventing the directory creation or restarts.