Mainstream support ended in 2018, and extended support ended in January 2023. However, some security updates are still available via paid Extended Security Updates (ESU) for enterprises. Running an unsupported OS is risky.

using NTLite. Remove language packs (keep English only), printer drivers (keep basic), and optional features like Hyper-V, PowerShell ISE, and Windows Insider Hub.

If you're concerned about the risks associated with highly compressed Windows 8.1 64 bit, there are alternative options:

: Some "lite" versions disable background services to lower RAM and CPU usage, theoretically improving performance on low-end PCs. Standard vs. Highly Compressed Requirements