By removing telemetry, Windows Defender, and dozens of background services, the OS feels significantly snappier than the stock version.

Test the ISO in VirtualBox or VMware to see if your essential apps even run.

While the idea of a "Windows Ultralight" build by FBConan sounds like a dream for anyone running an older laptop or a resource-heavy gaming rig, you should approach these custom ISOs with a mix of excitement and caution. What is Windows Ultralight (Build 22621.590)?

This is a "debloated" version of Windows 11 (22H2). FBConan is a well-known developer in the custom OS scene who specializes in stripping Windows down to its bare essentials. The goal is to reduce the OS footprint so it uses less RAM, fewer CPU cycles, and takes up minimal disk space.

These ISOs usually bypass TPM 2.0 and Secure Boot requirements, making them popular for older hardware. The Trade-offs: Is it Right for You?

It’s common for these builds to idle at under 1GB of RAM.

The installed size is often a fraction of the standard 20GB+ Windows installation.

Often, Windows Defender and Windows Update are stripped or disabled. You are responsible for your own security.