It's an old realtek 5.1 PCI card that came with the computer. When I go into audio set up the options are: WASAPI speakers, WASAPI Digital, WASAPI, high definition, Magix low latency, WDM and MME. No idea what any of these mean but the only one that works properly is MME.

You should definitely look for an external USB audio interface with its native ASIO driver.

There are many brands and models out there, even the budget interfaces from Behringer would improve your situation significantly.