Use a trusted source for the KMSPico installer.

Windows 8.1 remains a popular choice for older hardware because it's lightweight and fast. However, without activation, you’re stuck with: An annoying "Activate Windows" watermark.

Locked personalization settings (can’t change wallpaper or themes). Frequent pop-up reminders. Top Activator: KMSPico (Official 2021 Version)

KMSPico is the gold standard for "definitivo" (permanent) activation. It works by emulating a Key Management Service (KMS) server locally on your machine, tricking the system into thinking it belongs to a corporate network.