Windows runners

Windows self-hosted runners are available since v2.4.0, and are ~6x cheaper than the official GitHub Actions Windows runners on spot, and about 3x cheaper on-demand (for example on the m8i family). See pricing for current rates.

jobs:
  build:
    runs-on: runs-on=${{ github.run_id }}/image=windows25-full-x64/family=m8i

runners = {
  windows = {
    family = ["m8i.large"]
    image  = "windows25-full-x64"
  }
}

fleets = {
  windows = {
    runner = "windows"
  }
}

jobs:
  build:
    runs-on: runs-on/fleet=windows/env=production

Default images#

Example#

name: Windows

on:
  workflow_dispatch:

jobs:
  default:
    runs-on: runs-on=${{ github.run_id }}/image=windows22-full-x64/family=m8i
    steps:
      - uses: runs-on/action@v2
      - name: Checkout
        uses: actions/checkout@v7
      - name: Check current dir and env variables
        run: |
          dir .
          echo $env:USERNAME
          echo $env:RUNS_ON_RUNNER_NAME
      - name: Logs
        run: |
          Get-Content -Path "C:\runs-on\output.log"
      - name: Users
        run: |
          Get-LocalUser | Format-Table -AutoSize Name,Enabled,PasswordLastSet

Inspecting agent logs#

On Windows runners, the RunsOn agent output is stored in C:\runs-on\output.log. Those logs are also shipped to the CloudWatch log group for EC2 instances.

Limitations#

• Windows runners are slow to boot (~1min for base images, ~2-3min for full images). Warm pools can reduce this to 20-30 seconds.
• Hyper-V-dependent workloads require explicitly opting into nested-virt on supported x64 families such as m8i.
• Some legacy or easily-installable software has been removed to ensure faster boot times and lower disk usage.