# Service Pack Installation Failure

## Problem

Service Pack installation fails with error message: "Unknown Error code: \536870921".

## Cause

You will encounter such an error when the Service Pack (SP) installable file extraction fails. This could happen if the SP is unable to find a volume with enough disk space for file extraction.

## Resolution

You can resolve this issue by clearing some files from the OS-installed drive and retrying the SP installation.

To check your hard disk space, follow the instructions given below:

- Double-click **My Computer**.
- Right-click the OS-installed drive (usually, this is the **C:** drive) and select **Properties**.
- On the **General** tab, note the amount of free space.

In case there is not enough free space to install the SP, you can employ one or more of the following methods to clean disk space:

*To clean the Temp directory, follow the instructions given below:*

To clean your Temp directory, you first need to determine its location on your hard drive. Then, delete the contents of the directory using an MS-DOS command or through Windows Explorer.

### Determine the Location of the Temp Directory

#### For User Temp Files

- Select **Start > Run**.
- Type `%temp%` and press **Enter**. This will list the contents of the User Temp folder.

#### For System Temp Files

- Select **Start > Run**.
- Type `temp` and press **Enter**. This will list the contents of the System Temp folder.

### Delete the Contents of the Temp Directory

Choose one of the following methods to delete the contents of the Temp directory.

**Note:** Do not delete the Temp directory itself. Delete only the files and folders in the directory.

#### Using an MS-DOS Command

1. Click **Start > Run**.
2. Type:

```
deltree /y temp_directory_location\*.*
```

For example:

```
deltree /y C:\Windows\Temp\*.*
```

`temp_directory_location` is the location of the Temp directory.

#### Through Windows Explorer

1. Double-click the **My Computer** icon on your desktop or select **Start > Explore**.
2. Navigate to the location of the Temp directory (for example, `C:\Windows\Temp`).
3. Select **Edit > Select All**.
4. Select **File > Delete**.
5. Click **Yes** or **Yes to All** in the dialog that appears.

**Note:** You can make use of the [Disk Clean Up](https://www.manageengine.com/desktop-management-msp/windows-system-tools.html) utility of the Endpoint Central application to remove unwanted files from the disk.

**Applies to:** Patch Management, Service Pack Installation

**Keywords:** Patch Management, Patch Deployment Failure, SP Installation, Unknown Error Code: \536870291