If you attached a new, blank disk to your VM, before you can use it you must
format and mount the disk. If you attached a disk that already contains data,
then you must mount the disk before you can use it.

## Before you begin

- If you haven't already, set up [authentication](https://docs.cloud.google.com/compute/docs/authentication). Authentication verifies your identity for access to Google Cloud services and APIs. To run code or samples from a local development environment, you can authenticate to Compute Engine by selecting one of the following options:

  Select the tab for how you plan to use the samples on this page:

  ### Console


  When you use the Google Cloud console to access Google Cloud services and
  APIs, you don't need to set up authentication.

  ### gcloud

  1.
     [Install](https://docs.cloud.google.com/sdk/docs/install) the Google Cloud CLI.

     After installation,
     [initialize](https://docs.cloud.google.com/sdk/docs/initializing) the Google Cloud CLI by running the following command:

     ```bash
     gcloud init
     ```


     If you're using an external identity provider (IdP), you must first
     [sign in to the gcloud CLI with your federated identity](https://docs.cloud.google.com/iam/docs/workforce-log-in-gcloud).

     > [!NOTE]
     > **Note:** If you installed the gcloud CLI previously, make sure you have the latest version by running `gcloud components update`.

  2. [Set a default region and zone](https://docs.cloud.google.com/compute/docs/gcloud-compute#set_default_zone_and_region_in_your_local_client).

  ### REST


  To use the REST API samples on this page in a local development environment, you use the
  credentials you provide to the gcloud CLI.
  1. [Install](https://docs.cloud.google.com/sdk/docs/install) the Google Cloud CLI.
  2. If you're using an external identity provider (IdP), you must first [sign in to the gcloud CLI with your federated identity](https://docs.cloud.google.com/iam/docs/workforce-log-in-gcloud).


  For more information, see
  [Authenticate for using REST](https://docs.cloud.google.com/docs/authentication/rest)
  in the Google Cloud authentication documentation.

## Connect to the VM

1. Go to the **VM instances** page.

   [Go to the VM instances page](https://console.cloud.google.com/compute/instances)
2. Click the **RDP** button next to the VM that has the new blank disk attached.
   The browser opens an RDP connection to the instance.

## Format and mount a non-boot disk on a Windows VM

Use the [Windows Disk Management utility](https://learn.microsoft.com/windows-server/storage/disk-management/initialize-new-disks)
to format and mount the new disk on a Windows VM.

1. Right-click the Windows Start button and select **Disk Management**.

   ![Selecting Disk Management by right-clicking the Windows Start button.](https://docs.cloud.google.com/static/compute/images/start_disk_manager_windows.png)
2. Disk Management prompts you to select a partitioning scheme for the new disk.
   Select **GPT** and click **OK**.

   ![Selecting a partition scheme in the disk initialization window.](https://docs.cloud.google.com/static/compute/images/initialize_disk_windows.png)
3. After the disk initializes, right-click the unallocated disk space
   and select **New Simple Volume**.

   ![Creating a New Simple Volume from the attached disk.](https://docs.cloud.google.com/static/compute/images/pd_new_volume_windows.png)
4. Follow the instructions in the **New Simple Volume Wizard** to configure
   the new volume. You can use any partition format that you like, but for
   this example select `NTFS`. Also, check **Perform a quick format**
   to speed up the formatting process. Optionally, set the cluster size
   in the **Allocation unit size** field. The cluster size
   [limits the maximum size of the partition](https://learn.microsoft.com/windows-server/storage/file-server/ntfs-overview).
   Keep this in mind if you try to resize the zonal persistent disk and this
   partition later.

   ![Selecting the partition format type in the New Simple Volume Wizard.](https://docs.cloud.google.com/static/compute/images/configure_new_volume_windows.png)
5. After you complete the wizard and the volume is formatted, check
   the `Status` column on the list of attached disks to ensure that the
   new disk has a `Healthy` status.

   ![Checking that the disk is online with a healthy status.](https://docs.cloud.google.com/static/compute/images/pd_healthy_windows.png)

You can now write files to the disk.

## What's next

- Learn how to [resize your persistent disks](https://docs.cloud.google.com/compute/docs/disks/resize-persistent-disk).
- Learn how to regularly [back up your disks using snapshots](https://docs.cloud.google.com/compute/docs/disks/create-snapshots) to prevent unintended data loss.