If it's greyed out then you are on an account that does not have rights to change it, or you are on a domain and group policy disabled the changes.
Log on to an administrator level account and try this.
But the main issue here is that Outlook will install no matter what type of network you are on, so you may want to start your question at the beginning here since you seem to be trying to do something you don't have to, or there are more things you need to work out.
You have a copy of Outlook, and your laptop, what exactly happens when you try to install it? Is this your own laptop or something from work? If it's from work, you should have your IT department install the program.