What Virtualization-Based Security Is and Why It Slows Old PCs
Virtualization-Based Security is a Windows security feature that uses the system’s hypervisor to isolate sensitive processes in a protected memory region, improving defense against malware but adding an extra processing layer that can noticeably reduce performance on older PCs. VBS creates a Virtual Secure Mode that runs separately from the normal operating system and checks low-level drivers, credentials, and kernel operations. Each time Windows switches between the normal OS and this secure area, the CPU performs a costly hyper-exit, adding latency to common tasks. On newer processors, hardware acceleration hides much of this cost. On 6th and 7th‑generation Intel Core chips and similar aging hardware, Windows relies on software emulation known as Restricted User Mode, which consumes valuable CPU cycles. Over time, this makes an old PC feel like it is “crawling” even when you are only doing basic work or browsing.
How to Confirm VBS Is Hurting Your Performance
Before you disable any Windows security feature, confirm it is a real cause of slowdowns. Start with Task Manager: press Ctrl+Shift+Esc and open the Performance tab to watch CPU usage and frequency while doing your normal tasks. If your system feels slow even with moderate CPU use, background security checks may be adding latency rather than obvious spikes. To see finer detail, use the Details tab. Sort by CPU time to reveal processes that have consumed a lot of processor time since startup, even if they are quiet right now. A security process with high CPU time in short bursts can make the system stutter. According to MakeUseOf, the Details tab “turned out to be the most informative view in Task Manager for diagnosing real performance issues,” because it exposes every process and many low‑level metrics.
Step-by-Step: Disable Memory Integrity (Core Isolation)
The main Windows security feature that drags down older hardware is Memory Integrity, part of Core Isolation, which runs under Virtualization-Based Security. To turn it off, open the Start menu, type Windows Security, and select the shield icon. In the left pane, click Device Security. Under Core isolation, select Core isolation details. On this screen, you will see the Memory Integrity toggle that controls virtualized checks on low-level drivers. Switch this toggle off. Windows will show a User Account Control prompt; confirm the change, then accept the notice that a restart is required. After rebooting, the hypervisor-based isolation layer is removed, freeing your CPU from constant virtual context switching. Windows Security may show a yellow warning triangle in the system tray to remind you that a recommended security feature is disabled; this is expected and indicates the change you made rather than a new problem.
Staying Safe After Disabling VBS on an Old PC
Turning off VBS and Memory Integrity trades a layer of protection for better performance, so you should compensate with other security practices. Keep Microsoft Defender or another reputable antivirus enabled for real-time scanning, and schedule full scans during idle hours to avoid slowdowns. Make sure Windows Update and your main applications stay current so known vulnerabilities are patched promptly. Avoid installing unsigned or unknown drivers, since Memory Integrity was helping to check those in a secure environment. Be careful with downloads, email attachments, and browser extensions. For risky activities such as testing software, consider using a separate, newer machine or a dedicated virtual machine on more capable hardware. As MakeUseOf notes, while VBS and Hypervisor-Protected Code Integrity make Windows 11 safer by blocking kernel-level exploits, on an old desktop “keeping that security layer isn’t worth crippling the machine’s basic functionality.”
When Disabling This Windows Security Feature Makes Sense
This Windows performance optimization is not for everyone. Disabling VBS-backed Memory Integrity is most helpful on older systems where the CPU lacks modern hardware acceleration and everyday tasks feel sluggish even after you remove bloatware and limit startup apps. It is a practical option for home users who want an old PC faster for web browsing, office work, or streaming and who maintain good security habits. On newer processors, the performance penalty is much smaller, so it is usually better to keep VBS enabled for the extra protection against kernel-level attacks and malicious drivers. If your PC is used for sensitive work, handles confidential data, or runs line-of-business software, keep all Windows security features enabled and look for other ways to speed up a slow PC, such as upgrading storage, adding RAM, or tuning background apps instead of weakening isolation.