An error message comes up telling me 'An unsupported media type was requested' - HD Audio input 1/HD Audio input 2 does not support 44,100 Hz at 16 bits - the RealTek ASIO driver doesn't seem to support anything.
When I try changing the driver to Windows in SF playback changes but record has ERROR
Try using MS Sound Mapper or Windows Classic Wave driver which are usually trouble free with internal sound card PCs, An ASIO driver is usually not needed in Sound Forge. You can also try a different sample-rate when you create a 'File> New' window for recording. Typically 44.1 or 48 kHz,16 or 24 bit
btw, welcome to the Magix Sound Forge users community @Adrian-Gooderham.