Windows PowerShell command on Get-command Undo-Transaction

NAME
    Undo-Transaction
    
SYNOPSIS
    Rolls back the active transaction.
    
    
SYNTAX
    Undo-Transaction [-Confirm] [-WhatIf] []
    
    
DESCRIPTION
    The Undo-Transaction cmdlet rolls back the active transaction. When you roll back a transaction, the changes that 
    were made by the commands in the transaction are discarded and the data is restored to its original form.
    
    If the transaction includes multiple subscribers, an Undo-Transaction command rolls back the whole transaction for 
    all subscribers.
    
    By default, transactions are rolled back automatically if any command in the transaction generates an error. 
    However, transactions can be started by using a different rollback preference and you can use this cmdlet to roll 
    back the active transaction at any time.
    
    The Undo-Transaction cmdlet is one of a set of cmdlets that support the transactions feature in Windows 
    PowerShell. For more information, see about_Transactions.
    

PARAMETERS
    -Confirm []
        Prompts you for confirmation before running the cmdlet.
        
        Required?                    false
        Position?                    named
        Default value                False
        Accept pipeline input?       False
        Accept wildcard characters?  false
        
    -WhatIf []
        Shows what would happen if the cmdlet runs. The cmdlet is not run.
        
        Required?                    false
        Position?                    named
        Default value                False
        Accept pipeline input?       False
        Accept wildcard characters?  false
        
    
        This cmdlet supports the common parameters: Verbose, Debug,
        ErrorAction, ErrorVariable, WarningAction, WarningVariable,
        OutBuffer, PipelineVariable, and OutVariable. For more information, see 
        about_CommonParameters (https:/go.microsoft.com/fwlink/?LinkID=113216). 
    
INPUTS
    None
        You cannot pipe input to this cmdlet.
    
    
OUTPUTS
    None
        This cmdlet does not return any output.
    
    
NOTES
    
    
        * You cannot roll back a transaction that has been committed.
        
        You cannot roll back any transaction other than the active transaction. To roll back a different, independent 
        transaction, you must first commit or roll back the active transaction.
        
        Rolling back the transaction ends the transaction. To use a transaction again, you must start a new 
        transaction.
    
    Example 1: Roll back the current transaction
    
    PS C:\>Undo-Transaction
    
    This command rolls back the current, active, transaction.
    Example 2: Start and roll back a transaction
    
    PS C:\>cd hkcu:\software
    PS HKCU:\Software> Start-Transaction
    PS HKCU:\Software> New-Item -Path "ContosoCompany" -UseTransaction
    PS HKCU:\Software> Undo-Transaction
    
    This example starts a transaction and then rolls it back. As a result, no changes are made to the registry.
    Example 3: Roll back a transaction for all subscribers
    
    PS C:\>cd hkcu:\software
    PS HKCU:\Software> Start-Transaction
    PS HKCU:\Software> New-Item -Path "ContosoCompany" -UseTransaction
    PS HKCU:\Software> Get-Transaction
    
    RollbackPreference   SubscriberCount   Status
    ------------------   ---------------   -----
    Error                1                 Active
    
    PS HKCU:\Software> Start-Transaction
    PS HKCU:\Software> Get-Transaction
    
    RollbackPreference   SubscriberCount   Status
    ------------------   ---------------   -----
    Error                2                 Active
    
    PS HKCU:\Software> Undo-Transaction
    PS HKCU:\Software> Get-Transaction
    
    RollbackPreference   SubscriberCount   Status
    ------------------   ---------------   -----
    Error                0                 RolledBack
    
    This example demonstrates that when any subscriber rolls back a transaction, the whole transaction is rolled back 
    for all subscribers.
    
    The first command changes the location to the HKCU:\Software registry key.
    
    The second command starts a transaction.
    
    The third command uses the New-Item cmdlet to create a new registry key. The command uses the UseTransaction 
    parameter to include the change in the transaction.
    
    The fourth command uses the Get-Transaction cmdlet to get the active transaction. Notice that the status is Active 
    and the subscriber count is 1.
    
    The fifth command uses the Start-Transaction command again. Typically, starting a transaction while another 
    transaction is in progress occurs when a script that is used by the main transaction includes its own complete 
    transaction. This example is performed interactively so that you can examine it in stages. When you run a 
    Start-Transaction command while another transaction is in progress, the commands join the existing transaction as 
    a new subscriber and the subscriber count is incremented.
    
    The sixth command uses the Get-Transaction cmdlet to get the active transaction. Notice that the subscriber count 
    is now 2.
    
    The seventh command uses Undo-Transaction to roll back the transaction. This command does not return any objects.
    
    The final command is a Get-Transaction command that gets the active, or in this case, the most recently active, 
    transaction. The results show that the transaction is rolled back, and that the subscriber count is 0, showing 
    that the transaction was rolled back for all subscribers.
    
RELATED LINKS
    Online Version: http://go.microsoft.com/fwlink/?LinkId=821648
    Complete-Transaction 
    Get-Transaction 
    Start-Transaction 
    Use-Transaction