What does your pc mother board have as far as on board sound? Most have 5.1/7.1 realtek chip on it which you can do DDL and DTS with provided it has 5/7.1 analog and spdif (or coaxial). Also keep in mind when looking for a card, on mobo, or add on, that it has 5.1 or 7.1 analog, and that your receiver has that too. Reason being is games that dont give you the option in menu to select that as sound out, using ddl or dtsi as your output sound will only play in stereo. To get around that you need to run some 3.5mm jacks to rca from your sound card to your receiver to get it to play in "surround" sound. Most "newer" 4K receiver no longer have these jacks on them, only outputs, and because of that I use older receiver units, most good ones that have 1080P hdmi inputs still have this external in's, and that way I can use my 4K tv as the HDMI switch, and run the spdif cable from my tv to my receiver. Most people dont know this and think they have to buy a 4K receiver, and then everything goes to it, then to the tv. In some cases if your not using the correct hdmi cable that doesnt do 4k at 60HZ (or better) and HDR, will not get everything the tv has to offer then direct plugging everything to the tv and just use the one spdif cable from the tv to any old receiver 4k or not. Of course the older receiver wont do atmos or DD+ and the like in some cases, need to check the specs on the receivers your planning on buying, but for a pc, a old receiver that isnt dolby pro logic only without dd or dts capabilities wont work good, so need something newer then that. Need to be little newer then that, and then you can run that one cable, one from your tv, and one from your computer (provided your on-board or sound card has spdif outs) to the receiver and be done with it. Then you just have to switch things on your pc in the sound setting between analog and digital to do surround sound, and switch the receiver to that input to match.
Since I dont know what harmon you got, or on-board or not, just be sure to get a sound card, usb or not, with both spdif and 5/7.1 analog outs to get the most of it all. And if your receiver doesnt have 5/7.1 analog external inputs I would just suggest you get one dirt cheap at
www.shopgoodwill.com, or off ebay and use that to make use of it all if surround sound in games/music/movies is what you are after.
I just saw and hit me, youre not in the US so the goodwill site may not be any good to you, but check your ebay for a good cheap receiver, they are a dime a dozen since most people think they have to have a 4K unit for their 4K tv, not understanding what the glowing red light in the back of the tv is for
