I hope 100 computers are not windows system because you took example of Ms office.
If all are Linux based systems, read ahead.
You can write a script for it. Start loop. Find all IP of 100 systems. Log into each system using ssh then install the package in each system using command line. End the loop
nmap is a program which helps you to detect all IPs of a LAN. Install nmap where you want to run the script.
It will ask password for each system. To solve this problem save your public key file in each system's .ssh directory as authorized_keys. Now you can log in without password.
Be advance and install puppet
. Puppet is a configuration management tool.
Or you can use other configuration management tools like puppet or similar one to do jobs like this.
It is always good to use new tools and technologies which are secure and reliable.