Preflight Checklist
What's Wrong?
[BUG] Claude Desktop spawns 1.8 GB Hyper-V VM on every launch, even for chat-only use
Environment
Note: This issue is specific to the Claude Desktop app (Windows), not Claude Code CLI.
OS: Windows 11 Pro 25H2, Build 26200.7840
Hardware: Razer Blade 15 Base Model (Late 2020), i7-10750H, 16 GB RAM
Claude Desktop: Latest version as of 2/26/2026
Windows Features: VirtualMachinePlatform enabled; Hyper-V, WSL, Docker, and Windows Sandbox are all disabled
Core Isolation / Memory Integrity: Off
Summary
The Claude Desktop app launches a Hyper-V virtual machine (Vmmem) consuming approximately 1.8 GB of RAM every time it starts — even when the user only needs chat functionality and has no intention of using Cowork or agent mode. On a 16 GB laptop, this represents over 11% of total memory consumed by infrastructure that isn't being used.
Steps to Reproduce
Install Claude Desktop on Windows 11 with VirtualMachinePlatform enabled
Use Cowork/agent mode at least once (this creates session files)
Close and reopen Claude Desktop — or simply reboot the machine
Open Task Manager and observe Vmmem consuming ~1,800 MB
What Happens
On every launch, the Claude Desktop app triggers the Hyper-V Host Compute Service (vmcompute) via an RPC interface event, which spawns a vmwp.exe process hosting a full virtual machine. This VM appears as "Vmmem" in Task Manager at approximately 1,796–1,846 MB.
The Hyper-V Compute Admin event log shows repeated errors:
"The specified property query is invalid: The virtual machine or container JSON document is invalid. (0xC037010D, 'Invalid JSON document '$'')"
These errors have been occurring since at least 2/19/2026, triggered on every boot and app launch.
Root Cause Investigation
Through extensive PowerShell diagnostics, we confirmed:
WSL is not installed — wsl --shutdown returns "not installed"
Hyper-V management tools are not installed — Get-VM fails
Docker is not installed — no Docker processes found
Windows Sandbox is disabled
Core Isolation / Memory Integrity is off (and was off before this issue started)
VirtualizationBasedSecurityStatus shows 2 (running), likely due to LSA Protection being enabled — but this alone doesn't explain the 1.8 GB VM
The only enabled virtualization feature is VirtualMachinePlatform
The vmcompute service is set to Manual start but is triggered at boot by an RPC interface event (GUID: bc90d167-9470-4139-a9ba-be0bbbf5b74d). The parent process is services.exe (PID 1400), confirming it's a service trigger, not a user-initiated launch.
We found 2,689 stale session files in %APPDATA%\Claude\local-agent-mode-sessions\ — all from previous Cowork sessions that were never cleaned up. Session names follow Docker-style naming (e.g., "nifty-dreamy-volta", "tender-vigilant-goodall", "admiring-elegant-johnson"). Even after deleting all 2,689 files and killing vmcompute/vmwp, simply reopening the Claude Desktop app immediately respawned the VM and the 1.8 GB Vmmem process.
Impact
On a 16 GB system, this bug causes memory usage to jump from ~50% to ~62% at idle before the user does anything. Combined with normal application load, this pushes total usage to 70–75%, causing system sluggishness and forcing the user to manually kill VM processes after every launch.
Expected Behavior
The Claude Desktop app should not spawn a VM for chat-only sessions
If Cowork infrastructure is needed, it should initialize on demand — only when the user actually starts a Cowork/agent session
Stale session files from previous Cowork sessions should be cleaned up automatically, not accumulate indefinitely (2,689 files in our case)
The app should fall back to chat-only mode if VM initialization fails or is unnecessary, rather than unconditionally starting VM infrastructure
Current Workaround
The only reliable workaround is to disable VirtualMachinePlatform entirely:
powershellDisable-WindowsOptionalFeature -Online -FeatureName "VirtualMachinePlatform" -NoRestart
This prevents the VM from launching but also disables Cowork functionality. Alternatively, the user can kill the VM processes after every launch:
powershellStop-Process -Name vmwp -Force
Stop-Process -Name vmcompute -Force
Chat functionality continues to work normally after killing these processes.
Request
Please modify the Claude Desktop app so that:
VM/container infrastructure only initializes when Cowork or agent mode is actively requested
Old session data is cleaned up automatically after sessions end
The app gracefully handles the absence of VM infrastructure without degraded chat performance
What Should Happen?
The Claude Desktop app should not spawn a Hyper-V VM (Vmmem, ~1.8 GB RAM) when launching for chat-only use. VM/container infrastructure should only initialize when the user actively starts a Cowork or agent session. Stale session files should be cleaned up automatically after sessions end.
Error Messages/Logs
Hyper-V Compute Admin log shows repeated errors on every boot:
"The specified property query is invalid: The virtual machine or container JSON document is invalid. (0xC037010D, 'Invalid JSON document '$'')"Steps to Reproduce
- Install Claude Desktop on Windows 11 with VirtualMachinePlatform enabled
- Use Cowork at least once
- Close and reopen Claude Desktop (or reboot)
- Observe Vmmem in Task Manager consuming ~1,800 MB at 0% CPU
Claude Model
Not sure / Multiple models
Is this a regression?
I don't know
Last Working Version
No response
Claude Code Version
Claude Desktop (Windows) latest as of 2/26/2026
Platform
Anthropic API
Operating System
Windows
Terminal/Shell
PowerShell
Additional Information
See detailed bug report in description above.
