If your desktop/laptop has multiple hp/3.5mm output jacks( 3 usually) and you can find the 5.1 surround sound setting in your sound cards GUI, you are good to go!
There might also be a quadrophonic surround(4 channels) option. You can use the 2 nd hp jack to feed your older pair of speakers. The only thing is you will need a long 3.5mm cable if your speakers are active, computer speakers or long speaker wires if you have a speaker+ separate amp setup.