====== Previews of Rhino files missing in Windows Explorer ======
> **Summary:** //How to make sure the Rhino thumbnail viewer is registered in Windows//

If you do not see preview thumbnails of Rhino .3dm files in Windows Explorer, the follow these steps.

=====1. Repair your Rhino installation=====

  - Click **Start -> Settings -> Apps & features**.
  - For **Rhino 7**:
    - Select **Rhino 7** and click **Modify**.
    - In the installation dialog box, click **Repair**.
  - For **Rhino 6**:
    - Select **Rhino 6** and click **Modify**.
    - In the installation dialog box, click **Repair**.
  - For **Rhino 5**:
    - Select **Rhinoceros 5 (64-bit)** and click **Modify**.
    - In the installation dialog box, click **Repair**.

If you do not see preview thumbnails of Rhino .3dm files, proceed to step 2.

=====2. Verify thumbnails are not disabled=====
  - Open **Explorer**.
  - Click **View**.
  - Click **Options** and then **Change folder and search options**.
  - Verify **Always show icons, never thumbnails** is NOT checked.
{{:rhino:folder_options.png|Folder Options}}


If you do not see preview thumbnails of Rhino .3dm files, proceed to step 3.

=====3. Delete the thumbnail cache===== 
If you are running an older Windows, like Windows 7, you may need to run Windows **Disk Cleanup** utility. 

  - Run **Disk Cleanup**.
  - Click **Thumbnails**.
  - Click **OK**.

{{:rhino:disk_cleanup.png|Disk Cleanup}}

If you do not see preview thumbnails of Rhino .3dm files, proceed to step 4.

=====4. Register the Rhino thumbnail viewer=====

To register the Rhino thumbnail viewer, you will need to open a Command Prompt as an Administrator.

===Windows 8 or 10===

To open a Command Prompt as Administrator on Windows 8 or 10:

  - Access by Power menu by pressing **Windows+X**
  - From the menu, select **Command Prompt (Admin)**

{{:rhino:window_x.png|Power Users menu}}

When you launch the Command Prompt with Admin privileges, you’ll likely see a **User Account Control** window asking for permission to continue. Go ahead and click **Yes**.

===Windows 7===

To open a Command Prompt as Administrator on Windows 7:

  - Click Start
  - In the search field, enter **CMD**.
  - In the results list, you will see **CMD**.
  - Right-click on **CMD** and from the context menu, select **Run as Administrator**.

{{:rhino:window_7.png|Command Prompt}}

When you launch the Command Prompt with Admin privileges, you’ll likely see a **User Account Control** window asking for permission to continue. Go ahead and click **Yes**.

====Register the Rhino Thumbnail Viewer====

===Rhino 7===

If you have Rhino 7 for Windows installed, then run the following command from the Command Prompt window you just opened:

  regsvr32 "C:\Program Files\Rhino 7\System\RhinoHandlers.dll"

===Rhino 6===

If you have Rhino 6 for Windows installed, then run the following command from the Command Prompt window you just opened:

  regsvr32 "C:\Program Files\Rhino 6\System\RhinoHandlers.dll"

===Rhino 5===

If you have Rhino 5 for Windows (and you don't have Rhino 6 for Windows installed), then run the following command from the Command Prompt window you just opened:

  regsvr32 "C:\Program Files\Rhinoceros 5 (64-bit)\System\RhinoHandlers.dll"