NO! Cover that hole in the back. Your PC is designed to manage air circulation and heat control with that space closed. You can actually cause more heat problems, not to mention additional dust collection, by leaving that hole open. Heat will prematurely age your PC.
djm
Surrreee… you whimp out and call it a moot point!
Ok - I taped the metal piece back in place. And I was careful not to cover up any of the holes with the tape.
Once the metal knockout plate has been removed, it’s best to install a screw in coverplate.
If the tape loosens, the metal knockout may touch the motherboard and short out something.
I have a bunch I salvaged from old computers. If you cannot get a free one from a local computer shop, PM me your address and I’ll mail one to you.
You can see some coverplates pictured here:
From this website:
http://www.homewurk.nl/homewurk/manual/NICinstal/nicinstal_en.html
You may all sleep well again knowing that I bought a cover plate and installed it.
Ahhhhh… I’m just up from an afternoon nap. I think I’ll round up my nephews and go out for sushi.