This powershell script will give you the ability to install windows updates on a remote computer.
The script will remotely create a scheduled task on the given computer with the needed powershell cmdlets to:

1. Search for updates
2. Download updates
3. Install updates

Powershell 4.0 is needed for the Register-ScheduledJob cmdlet.

    Force Install Updates on Remote Computer 
    Force Install Updates on Remote Computer using a scheduled task 
    InstallUpdates -Computer "" -User "Contoso\Administrator" -Password "Password" 
    Version 1.0 - Initial Script 
    Written by Darryl van der Peijl 
    Date: 30.05.2014 
    Use at own risk 
Function InstallUpdates { 
$SecurePassword = ConvertTo-SecureString –String $Password –AsPlainText -Force 
$Credential = New-Object –TypeName System.Management.Automation.PSCredential –ArgumentList $User$SecurePassword 

The script can install updates on client and serverside machines.