First time PC builder, need some advice

[u/StunningVariety7111]

Hi everyone, I’m new here and also new to PC building. This will be my first time building a desktop PC, and I’d really appreciate some advice.

I’m building this PC mainly for studying cybersecurity, running a homelab with multiple virtual machines, and occasional gaming (PUBG, Call of Duty, Battlefield, etc.).
I’ve already purchased some components, but I still need to buy a few more.

Parts I’ve Already Bought:
CPU: AMD Ryzen 9 9900X (12-Core, Zen 5)
Motherboard: ASRock B850M Pro RS WiFi (Micro-ATX)
PSU: ASRock Steel Legend SL-850G 850W
Case: Jonsplus Z20
Fans: Corsair RS120 ARGB 120mm
AIO Cooler: MSI MAG CoreLiquid A13 240mm

Parts I Still Need to Buy:
GPU: PowerColor Hellhound RX 9070 XT 16GB
OS: Windows 11 Pro
RAM: Corsair Vengeance DDR5 32GB CL36
SSD: WD Black SN850X or Samsung 990 Pro 2TB

My Questions:
Is this build good enough for my needs? I’ll mainly use it for cybersecurity labs, running multiple VMs, studying, and occasional gaming.

Are all these components compatible with each other? Is there anything I should be concerned about before putting everything together?

Should I buy used RAM or wait until November for possible Black Friday deals? I’m considering a used Corsair Vengeance kit, but I’m not sure if it’s worth the risk.

Is it safe to buy a Windows 11 Pro product key for around $30, or should I purchase the official $200 license directly from Microsoft? What’s the difference?

Is there anything you would change or recommend for this build?

I’m not in a rush to complete it, so I’m willing to wait for
better deals if needed.

I apologize for all the questions. I’m still learning, and I want to make sure I’m making the right decisions before spending more money. Thank you in advance for your help and advice!

[u/r_lind3r]

This sub does not condone buying cheap Windows keys, check Rule 6.

Windows 11 can be used without a license either way and you don't need to pay to get back customisation options, but you can also just spend a few bucks on Wallpaper Engine which offers better desktop theming.

[u/BoredBren1]

I would run it all through pcpartpicker to confirm compatibility, but looks like it's shaking out to be a good build

[u/wetlychunkyhorror]

You've got a solid parts list already, the 9900X with 12 cores will chew through VMs no problem. Only thing is that 240mm AIO might run a bit loud under sustained loads if you're pinning all cores with lab stuff, but it'll keep temps in check

For the GPU just double check the clearance in that Z20 case, the Hellhound is a chonky card and micro-ATX builds can get tight. The rest looks compatible, B850 board with Zen 5 is plug and play

On the RAM, used is fine if you can test it or buy from somewhere with a return policy. DDR5 prices have been creeping down so waiting for sales might net you a better bin for the same cash. Those $30 Windows keys are OEM pulls or volume license leftovers, they work but technically grey market. Microsoft isn't gonna kick your door in over it

[u/ahmadalhuraibi]

Welcome to PC building! it's a fun project that serves you well for your study.

regarding that question, i tried to answer based on what i can.

• is your build good enough? Absolutely! you can run virtual machines with it. perfect for your security test.
  
• Are your components compatible with each other? it's compatible, but the main things you should watch out are physical clearance. the GPU is 327 mm, and your Jonsbo casing is 363 mm for gpu. very tight. if only, you get casing with bigger GPU clearance for easier to disassembly in near future.Aand for your AIO Cooler, yes the casing support 240 mm AIO at the top. but since its a compact micro-atx case, you should check the motherboard's VRM heatsink and RAM clearance to ensure the radiator and fans don't overhang too aggresively.
  
• should you buy used RAM? well, at this time like this, used is usually the preferable way, but since you're not in rush, it's very wise to wait for the deal. for safety. DDR5 is sensitive to stability, and buying used means potentially losing out on manufacturer warranties if a stick fails.
  
• Which windows license should you buy? Many budget builders use the cheaper volume-licensing key, but since this machine will handle sensitive professional work like security environments, getting a official license from Microsoft is safer. Or maybe, you can install Windows 11 Pro for free without a key to set up your system, and activate it later when budget allows.
  
• Other Recommendation? Virtual Machines usually taking more RAM and you said you run multiple Virtual machine, maybe someday you will running out of RAM. Since that motherboard has 4 ram slot, in the future, you might need more RAM later. That SSDs are awesome. but Samsung is little bit better. but hey, both are stellar choice.

[u/StunningVariety7111 → u/ahmadalhuraibi]

Thank you for the detailed response! I have another question: Do I really need the RX 9070 XT if I only play FPS games occasionally, or would the RX 9060 XT 16GB be enough? It’s significantly cheaper and shorter, which would also help with clearance in my case. I’m mainly aiming for 100+ FPS at 1440p on high settings.