The issue with the bypass of the security checks is that M$ lets you install security updates, but not feature packs -- you need to reinstall with the media creation tool, or if that fails bootable media with the CPU/TPM bypass applied in Rufus. Sadly, the only way around this problem for the foreseeable future is to get a supported CPU (8th gen Intel, Ryzen 3rd gen/some non-Ryzen chips).
I ABSOLUTELY HATE TO SAY THIS but do what I did to get around their manufactured "problem": Grab a machine with a supported Intel CPU (9th-present) or Ryzen processor (at least 3000 series, unless it is on the Supported CPU list) or an upgradeable system which can be easily tweaked as needed (read: use caution with newer Dell/HP/Lenovo prebuilts) unless you want to custom build with an open market board+CPU combo that will take a supported CPU. Even if the initial CPU your combo comes with is "unsupported" THAT IS FINE, pick up a compatible CPU if the price agrees with you to make up for that; I've done both. Either keep it for flashing or resell it if it's worth reselling once the return window expires. The catch is if you go that route just make sure to apply the newest BIOS updates with the old CPU installed initially. For cases if you're comfortable and willing to tweak the old chassis you can swap out the FP wiring on these for the power button and such with replacements used in open market cases, but this is usually not worth it on these "sardine can metal" HP cases. Get a good case like a Thermaltake and move what you can over.
While you will need a new CPU, mobo, and RAM and won't be able to reuse the original HP power supply (275-300W junk cheapos, HP is no better except it doesn't kill the motherboard unlike the Bestec ATX-250-12E the OEMs loved at one point). About the only things that will move are the hard drive and DVD drive. Leave the Ralink WLAN card in the past, they were bought out for IP and the wireless cards were abandoned.
The main goal here is not to buy a new machine unless you really want to do a good custom build or keep it for another 10 years, it's to get you into a reasonably new platform that is already depreciated due to gamer surplus but is very good even today.
This is the spec I picked for my "11 ready" build:
- i5 9400f (f=GPU REQUIRED), but my recommendation has changed here: look for an 11th gen board and CPU. Prices are appealing now.
- 256GB NVMe SSD (Teamgroup)/16GB DDR4 (Teamgroup)
- 1TB scratch drive (WD Blue, pulled from old XPS 8500)
- Some old Fermi GTX I had that couldn't even be offloaded during the shortage due to it's age, temporary