Hi there, I am building a new desktop and the area that it will be located in is upstairs from the router. I have had issues in the past with wifi devices in this area just getting fairly weak signals so I am considering getting powerline instead. My wifi option is an onboard card
I just recently had the same issue, My PC is upstairs and there is a lot of interference just killing the wifi signal in my house. The router being at the exact opposite side of the house didn't help either. I was using a wifi extender to resolve this, which was terrible because it more than halved the bandwidth. I couldn't use powerline adapters because the wiring in my house is so old and cheap it wouldn't have worked very well at all.
In the end I ran a CAT5 cable all the way from the router up to my room. If powerline adapters will work in your house I would recommend using those. I actually have the exact same wifi card and its a good one, but that didn't mean anything when the signal was terrible.
So that's my long way of saying, cable is the way for a desktop. Especially if wifi signal is poor.