Here's what I did to get higher performance and security across the board for Windows 10/11 (minimize using earlier versions of any operating system if it's no longer being updated for security).
Hardware - mid-range CPU like an i5, at least 16 GB RAM, SSD, sufficient cooling system (either three or more large fans or all-in-one liquid cooling system).
Bonus: a large-enough casing (not necessarily full tower) such that it'd be easy to clean the insides or remove or replace parts; the new ones with glass walls or windows are helpful, and casing colored brown or white if you want to clean the vents; those with magnetic mesh covering fans are great. I put the casing outdoors and use a blower to clean the insides, but I have to put chopsticks between fan blades or tape them so that they won't move.
Software -
Kerish PC (paid; look for promos with large discounts) (for free, you can also use free versions of Glarysoft or WiseCare; for open-source, try Hellzerg's Optimizer, and to repair the system if needed, FixWin, for stalling, slowdowns, etc.); in all cases, check out the Internet tweaks that can speed up browsing; for free hardware monitoring software, try HWINFO coupled with CrystalDiskInfo.
Kaspersky Standard (you can also use free, but you'll using the Windows firewall; you can also use Avast free--not Avast One--and try to use silent mode and do-not-disturb mode to minimize popups; it comes with a firewall) (you can probably turn off core isolation, etc., in Windows Security because these security programs usually have virtualization).
Firefox browser tweaked using Betterfox (speeds up browsing), with Adguard for desktop (paid; look for promos for lifetime subscriptions; for free, try uBlock Origin addon) (check out the multi-account containers addon).
Look for a fast DNS near your place using
Fastest DNS Speed Test - Find Optimal DNS Server | No Install
and then after configuring it in Firefox (in enable DNS over HTTPS) see if browsing speeds up.
You can also test the security features and speed of the DNS you selected using
dnscheck.tools - check your dns resolvers
You can also configure that in the Windows 11 network settings or in your router, if you wish.
Backup: AOMEI (look for promos for lifetime licenses; for free software, Hasleo Backup) (backup to another drive, preferably external; the backup scheme is up to you; if you lack space, then you can probably do a full backup and daily incrementals, and then the set deleted periodically for a new full backup; in my case, it's monthly; also, make a rescue disk). Optionally, you can also backup some folders to Google Drive or another service automatically.
Downloaders - Internet Download Manager (paid; look for cheap licenses in various stores; for free, you can use Jdownloader2 (look for the ad-free installer) and Xtreme Download Manager; these can do fast regular downloads but also capture or get the URLs of video and audio files from various sites).
Others:
Set Windows to update every four or five weeks; let the others be used as beta testers.
Use Autoruns (free) and check Services in Windows to see what you can disable or set to manual instead of running automatically during startup.
You can install various secondary scanners, like Norton Power Eraser, Malwarebytes, Panda Cloud Security, ESET Kit, etc., but make sure that they don't run in real-time.
For a privacy browser that you can use for various purposes, maybe Mullvad (uses Mullvad DNS by default and uBlock Origin; exclude it in Adguard if you use that).
For free VPN that you might need for one thing or another, UrbanVPN (lots of countries to select) and PrivadoVPN (you can probably set anything they add in Services to manual, and disable anything that they run automatically).