The basic board spec shows it does not have a Serial port. However it does have an Intel Management Engine interface for which the drivers should be here.
Lenovo ThinkCentre M58 (7360CU7) Drivers Download This page contains the list of device drivers for Lenovo ThinkCentre M58 (7360CU7). To download the proper driver, first choose your operating system, then find your device name and click the download button. T420s Laptop (ThinkPad) Please Select. Back Windows 7 (64-bit). Desktops and all in ones:: thinkcentre m series desktops:: thinkcentre m91p Lenovo PC Support - US.
If you read the driver page it informs that if these drivers are not installed it shows as missing drivers for a Simple Communications controller.
To be clear serial ports are legacy devices and seldom used today. If not actually needed the lack of drivers for this specific device would have no effect on the system
The specification also says nothing about a parallel port (Lpt1). Do you have an expansion card into which you plugging in the printer. The socket would not be in the main group of connectors but separate and in the vertical slots. Some port expansion cards had both Serial and parallel ports so this might be the missing driver. If so you would need to identify what the card is and find the appropriate drivers. Unfortunately it is highly likely they would not be available for Windows 7.
Pci Serial Port Driver Lenovo X220
The spec of the Printer does not show USB so have you got a USB to Parallel converter, In which case that is going to need drivers itself. Venerable and functional it may be but the 710c is a very old printer and although it may work if set up right is not supported on Windows 7.