1. An information processing system having a terminal apparatus, an information processor, and an image processor connected to one another, wherein the information processor comprises: a first virtual machine; a second virtual machine; a first receiving unit that receives a connection request from the image processor connected to the information processor via a network; a first forwarding unit that forwards the connection request received by the first receiving unit to the first virtual machine of the information processor; a second receiving unit that receives a connection request from the terminal apparatus connected to the information processor via the network; and a second forwarding unit that forwards the connection request received by the second receiving unit to the second virtual machine of the information processor, wherein the second virtual machine comprises: an acquiring unit that, upon receipt of identifying information of the image processor selected by a user via the terminal apparatus, acquires first virtual machine identifying information for identifying the first virtual machine on the basis of the identifying information of the image processor; and a transferring unit that transfers a connection authority to connect to the terminal apparatus and a job set by the user and received via the terminal apparatus to the first virtual machine on the basis of the acquired first virtual machine identifying information, and wherein the first virtual machine comprises a connecting unit that connects the first virtual machine and the image processor upon receipt of the connection authority from the second virtual machine.