Application Notes:
A Windows box does not make a good firewall and was never intended to.
A Windows box does not make a good router and was never intended to.
A Windows box might make decent file server, if the admin knows what she is doing.
A single Debian box should not be performing all three functions simultaneously.
The past tense of 'throw' is 'threw' - not 'through.'
A well-planned firewall, router, fileserver or VPN deployment is not 'thrown' together in a couple of hours, no matter what platform it is based upon.