Restarts ("reboots") the operating system on local and remote computers.

Syntax

Restart-Computer [[-ComputerName] <string[]>] [[-Credential] <PSCredential>] [-AsJob] [-Authentication {<Default> | <None> | <Connect> | <Call> | <Packet> | <PacketIntegrity> | <PacketPrivacy> | <Unchanged>}] [-Force] [-Impersonation {<Default> | <Anonymous> | <Identify> | <Impersonate> | <Delegate>}] [-ThrottleLimit <int>] [-Confirm] [-WhatIf] [<CommonParameters>]

Description

The Restart-Computer cmdlet restarts the operating system on the local and remote computers.

You can use the parameters of Restart-Computer to run the restart operations as a background job, to specify the authentication levels and alternate credentials, to limit the operations that run concurrently, and to force an immediate restart.

This cmdlet does not require Windows PowerShell remoting unless you use the AsJob parameter.

Parameters

-AsJob

Runs the command as a background job.

Note: To use this parameter, the local and remote computers must be configured for remoting and, on Windows Vista and later versions of Windows, you must open Windows PowerShell with the "Run as administrator" option. For more information, see about_Remote_Requirements.

When you use the AsJob parameter, the command immediately returns an object that represents the background job. You can continue to work in the session while the job completes. The job is created on the local computer and the results from remote computers are automatically returned to the local computer. To manage the job, use the Job cmdlets. To get the job results, use the Receive-Job cmdlet.

For more information about Windows PowerShell background jobs, see about_Jobs and about_Remote_Jobs.

Required?

false

Position?

named

Default Value

none

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Authentication <AuthenticationLevel>

Specifies the authentication level that is used for the WMI connection. (Restart-Computer uses WMI.) The default value is Packet.

Valid values are:

Unchanged: The authentication level is the same as the previous command.

Default: Windows Authentication

None: No COM authentication

Connect: Connect-level COM authentication

Call: Call-level COM authentication

Packet: Packet-level COM authentication.

PacketIntegrity: Packet Integrity-level COM authentication

PacketPrivacy: Packet Privacy-level COM authentication.

Required?

false

Position?

named

Default Value

4

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-ComputerName <string[]>

Specifies one or more remote computers. The default is the local computer.

Type the NETBIOS name, an IP address, or a fully qualified domain name of a remote computer. To specify the local computer, type the computer name, a dot (.), or "localhost".

This parameter does not rely on Windows PowerShell remoting. You can use the ComputerName parameter even if your computer is not configured to run remote commands.

Required?

false

Position?

1

Default Value

.

Accept Pipeline Input?

true (ByPropertyName)

Accept Wildcard Characters?

false

-Credential <PSCredential>

Specifies a user account that has permission to perform this action. The default is the current user.

Type a user name, such as "User01" or "Domain01\User01", or enter a PSCredential object, such as one from the Get-Credential cmdlet.

Required?

false

Position?

2

Default Value

Current user

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Force

Forces an immediate restart of the computers.

Required?

false

Position?

named

Default Value

False

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Impersonation <ImpersonationLevel>

Specifies the impersonation level to use when calling WMI. (Restart-Computer uses WMI.) The default value is "Impersonate".

Valid values are:

Default: Default impersonation.

Anonymous: Hides the identity of the caller.

Identify: Allows objects to query the credentials of the caller.

Impersonate: Allows objects to use the credentials of the caller.

Required?

false

Position?

named

Default Value

Impersonate

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-ThrottleLimit <int>

Specifies the maximum number of concurrent connections that can be established to run this command. If you omit this parameter or enter a value of 0, the default value, 32, is used.

The throttle limit applies only to the current command, not to the session or to the computer.

Required?

false

Position?

named

Default Value

32

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-Confirm

Prompts you for confirmation before executing the command.

Required?

false

Position?

named

Default Value

none

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

-WhatIf

Describes what would happen if you executed the command without actually executing the command.

Required?

false

Position?

named

Default Value

none

Accept Pipeline Input?

false

Accept Wildcard Characters?

false

<CommonParameters>

This cmdlet supports the common parameters: -Verbose, -Debug, -ErrorAction, -ErrorVariable, -OutBuffer, and -OutVariable. For more information, see about_CommonParameters.

Inputs and Outputs

The input type is the type of the objects that you can pipe to the cmdlet. The return type is the type of the objects that the cmdlet returns.

Inputs

None

You cannot pipe input to this cmdlet.

Outputs

None or System.Management.Automation.RemotingJob

When you use the AsJob parameter, the cmdlet returns a job object. Otherwise, it does not generate any output.

Notes

This cmdlet uses the Win32Shutdown method of the WMI WIN32_OperatingSystem class.

Example 1

C:\PS>restart-computer

This command restarts the local computer.






Example 2

C:\PS>restart-computer -computername Server01, Server02, localhost

This command restarts two remote computers, Server01 and Server02, and the local computer, identified as "localhost".






Example 3

C:\PS>$j = restart-computer -computername Server01, Server02 -asjob 

C:\PS> $results = $j | receive-job

C:\PS> $results

These commands run a Restart-Computer command as a background job on two remote computers, and then get the results.

The first command uses the AsJob parameter to run the command as a background job. The command saves the resulting job object in the $j variable.

The second command uses a pipeline operator to send the job object in $j to the Receive-Job cmdlet, which gets the job results. The command saves the results in the $results variable. 

The third command displays the result saved in the $results variable.

Because the AsJob parameter creates the job on the local computer and automatically returns the results to the local computer, you can run the Receive-Job command as a local command.






Example 4

C:\PS>restart-computer -comp Server01 -impersonation anonymous -authentication PacketIntegrity

This command restarts the Server01 remote computer. The command uses customized impersonation and authentication settings.






Example 5

C:\PS>$s = get-content domain01.txt

C:\PS> $c = get-credential domain01\admin01

C:\PS> restart-computer -computername $s -force -throttlelimit 10 -credential $c

These commands force an immediate restart of all of the computers in Domain01. 

The first command gets a list of computers in the domain and saves it in the $s variable.

The second command gets the credentials of a domain administrator and saves them in the $c variable.

The third command restarts the computers. It uses the ComputerName parameter to submit the list of computers in the $s variable, the Force parameter to force an immediate restart, and the Credential parameter to submit the credentials saved in the $c variable. It also uses the ThrottleLimit parameter to limit the command to 10 concurrent connections.






See Also