Legacy System

An outdated, obsolete computer system that no longer serves any use as it cannot perform the necessary tasks required of it.

Can also be used as insult to incompetent or feeble human beings.

"Yo dude, Is that excel 97 you're using?!?"
"Yea my company is too cheap to update their software. Upper management is focused on maximizing revenue."
"Ha! What a legacy system."

"Ha look at that dweeb!"
"OMG lol, what a legacy system."