How to manually reinstall the Windows Agent

ISSUE

Need to install or reinstall a Unitrends Windows agent.

RESOLUTION

NOTE OF WARNING: The installation or uninstallation of any MSI package CAN RESULT IN AN UNPLANNED REBOOT OF YOUR WINDOWS SERVER!  This is a function of msiexec.exe, NOT the Unitrends Agent, and is triggered when prior 3rd party installers or windows updates have set a reboot flag on prior installations and a reboot has NOT YET happened when another installer is later run and that interacts with windows service registration or kernel drives as backup products must.  This may make it appear the later installer improperly triggered a reboot but that is not the case.  The Unitrends installer never initiates a reboot itself, however, msiexec may trigger the pending uncompleted reboot of prior installers when another installer runs.  Unitrends has noted this situation seems to be especially common on Hyper-V hosts due to the complexity and hesitancy of planning maintenance/outages for host servers especially in small environments (as such they're more commonly found pending reboots than some other server roles), but this can happen on any Windows OS system. 

To avoid unexpected impact in production, either be sure there are no pending reboots of your system from other products before installing the Unitrends agent, or ensure your server is in a state where a reboot will not negatively impact it during an upgrade or installation.  For hyper-V hosts, Unitrends recommends ensuring guests are migrated to other cluster nodes or guests are able to be rebooted or shut down without production impact.  Only ever upgrade any one node of a cluster concurrently so that if a reboot is triggered failover will not be impacted.    

Unplanned reboots during agent installation are actually very, very rare, but following the above advice can reduce them to zero.  

1. If there is a Windows agent that is already installed, uninstall it using the Add / Remove Programs feature.  
   1. If you have problems uninstalling the agent, see the KB article Unable to uninstall Windows Agent.
   2. ​Rename the old PCBP folder to PCBP.old (just in case we need any logs at a late time).   
2. You will now need access to the installation agent. There are two different sources you can use:
   1. Navigate to the network share on the Unitrends appliance.  
      1. To do this, open a Windows Explorer and type in the IP address of the appliance, such as: \\192.168.25.25
      2. Open the Windows Agent folder and locate the correct 32 or 64 bit version of the agent that you need. Note:This is preferable to downloading the agent from the website as you will use the same version of agent that corresponds to the version that is installed on the Unitrends appliance.  
      3. Copy the needed agent file down to the server you are installing it on. (This will save future headache when trying to uninstall)
   2. Go to the Downloads page and download the needed version to the server.  Verify that you have the correct 32 or 64 bit version. 
3. Double click the agent installer and finish up the installation. 
4. Add the client if necessary on the Unitrends box.  
5. Start a new backup job for the server that has the new agent to verify that everything is working correctly.  

Note: In Unitrends Version 9.0 or higher, agent push has been expanded and assets should be added using the Protected Assets menu: http://www.unitrends.com/documents/rs-ueb-admin-guide/#../Content/satori/managing_protected_assets.htm
Manual installation is only needed for hyper-V hosts, cluster nodes, or operating systems that do not support agent push.
(Strongly suggest having an open maintenance window for any host related agent updates)