"desktop" is not a model number, it's only a term that can apply to thousands of computers, each requiring a unique set of drivers. I'm afraid I cannot help based on your vague hardware description. Last time I checked, Matsonic WAS a motherboard manufacturer, not a desktop maker. I say "WAS" because they're no longer in business.
To find make and model of pc hardware, EVEREST Home Edition
is a free system diagnostics, system information program that will id most hardware on-board a mb. as well as the actual motherboard. It will, in some cases, actually provide a download link for the driver.
Alternate Everest download link: (offers 2 sites to dl program from)
Run the program and then:
Click on Computer
Click on Summary
Right hand window (hardware) if the text is BLUE
this is a link to the web site for that particular hardware.
If you have additional questions or need further help, please post copy and paste of the COMPUTER SUMMARY report (Leave out the Debug –PCI section) from Everest.