Unsupported CPU: CPU does not have POPCNT!

Hate to break it to you (really), but that PC was never going to run Apex at adequate performance anyway, regardless of POPCNT.

The GTX 745 was already the 'low/medium range' part when it was released back in Feb. 2014.

Back then, its siblings the GTX 750 and - more so - the GTX 750 Ti were the prized 'affordable' gaming cards, providing PS4-like results.

The 745 was the underclocked and vastly under-cored edition.

I'm afraid with your Q9400 running at the stock 2.6Ghz paired with that GTX 745 - this wouldn't result in a great experience in Apex, even if your processor type was patched to be retrocompatible with POPCNT. Not sure how much VRAM your version of the 745 has either. If it's low, another big obstacle for modern games is low GPU vram.

Like, maybe you could squeeze by at 720p and 30-40fps, w/ low image quality settings.

I can run the likes of PUBG, Blackout, etc. at 1080p/60fps~ using High settings on a similar generation Intel quad CPU -- the Xeon X5470, but I overclock it past 3.8Ghz and I have 16GB of fast DDR3 system ram, plus my GPU is a recent RX 580 8GB edition. So I brute force this older rig to very nice 1080p gaming.

Given its performance and image quality in all other major Battle Royale titles and recent 2019 AAA game releases, I have no doubt it would manhandle Apex Legends at 1080p.

I've compared my 1070 to the RX 580 in many cases (on a 4.2Ghz i7) and when constricted to 1080p they're practically equal GPUs. Obviously the 1070 peels off ahead at 1440p.

Anyway, unfortunately that Xeon CPU also left the factory without POPCNT support sowed into its silicon, so it can't even launch Apex.

POPCNT is a rather trivial instruction set to go in and refactor in the compiler and patch, non-essential to runtime/in-engine gameplay, and several other games have been patched to remove the ill-advised restriction - handled by basic SSE 4.x instruction set retro-compatibility.

TL:DR: Nope, you can't launch Apex Legends. The game is currently flagged in such a way that POPCNT is a barrier to entry for your CPU.

Even if you could, your PC as per listed specs is likely to struggle in recent multiplayer games unless boosted in some areas.

(Fortnite/Overwatch are exempt - they run well on potatoes).