What is the proper name for this IT job?

I have been working in IT (network\system administration) for several years. Everywhere I worked for a company whose product was IT weather it be a webhost or an ISP. Naturally I worked a M-F 9–5.

I am looking to find a career where I would be the “company IT guy”. I would like to be responsible for the systems of a company that does something other than IT. A family friend of mine makes upwards of $100k a year working for a mid size financing company. Since it is not an IT company he is essentially his own boss as he is the sole person in the company responsible for the systems. He essentially keeps everything working and the company is happy.

What would this career be formally called? Everything on monster, dice, etc. are IT companies looking to hire IT people (software firms, ISPs, webhosts, etc.).