#The script need:
#List the VMs name where remove e reinstall the agent (file c:\vdi.txt or where you want)
#Share where is the horizon agent installation file and the file agentinstallv8.bat that contain the silent command for installation
#When the script start ask the vCenter Credential and the Admin User Credential for install the Horizon Agent on the VM
#Credential for access to vCenter
$credential = Get-Credential
#Credential with administrator role for install horizon agent 
$VMCredential = Get-Credential
#vcenter
$vcenter = "<FQDNvCenter>"
#List of VMs where remove e install new agent version
$VDIs = Get-Content "c:\vdi.txt"
connect-viserver $vcenter -Credential $credential
foreach ($VDI in $VDIs){
$VM = Get-VM -Name $VDI
Write-Host "Start remove agent from $VM"
#Script for verify if the agent is installed
$script = @"
Get-WmiObject Win32_Product -filter "Name='VMware Horizon Agent'" | Select Caption 
"@
#Script for remove
$removeapp= @"
wmic Product Where "Name='VMware Horizon Agent'" Call Uninstall /NoInteractive
"@
$value = Invoke-VMScript -VM $VM -ScriptType Powershell -ScriptText $script -GuestCredential $VMCredential 
#Check if horizon agent are install if present the script remove it and reboot the VM
if ($value.ScriptOutput -like "*Horizon*") {
     Write-Host "Horizon agent is installed"
     Invoke-VMScript -VM $VM -ScriptType Powershell -ScriptText $removeapp -GuestCredential $VMCredential -RunAsync
     While(Test-Connection $VM -Quiet -Count 1){
        Write-Progress -Activity "Rebooting $VM" -Status "Waiting for $VM to shut down."
        Start-Sleep -sec 1
     }
     While(!(Test-Connection $VM -Quiet -Count 1)){
        Write-Progress -Activity "Rebooting $VM" -Status "Waiting for $VM to come back up."
        Start-Sleep -sec 1
     }
     if ($value.ScriptOutput -cnotlike "*Horizon*") {
     Write-Host "Agent removed from $VM and $VM rebooted"
     } 
   }
   else { 
   Write-Host "Horizon agent is not installed on $VM" 
   } 

#####Agent Installation
Write-Host "Start the Horizon Agent installation in $VM"
Sleep 15 
#Installation with share change the fileserver,the share name, the labl and the file 
$installapp = @"
New-PSDrive -Name "S" -Root "\\vimng03\share" -Persist -PSProvider "FileSystem"
S:\agentinstallv8.bat
"@
Invoke-VMScript -VM $VM -ScriptType powershell -ScriptText $installapp -GuestCredential $VMCredential -RunAsync
While(Test-Connection $VM -Quiet -Count 1){
        Write-Progress -Activity "Rebooting $VM" -Status "Waiting for $VM to shut down."
        Start-Sleep -sec 1
    }
While(!(Test-Connection $VM -Quiet -Count 1)){
        Write-Progress -Activity "Rebooting $VM" -Status "Waiting for $VM to come back up."
        Start-Sleep -sec 1
    }
Write-Host "$VM after installation is UP" 
$value = Invoke-VMScript -VM $VM -ScriptType Powershell -ScriptText $script -GuestCredential $VMCredential
if ($value.ScriptOutput -like "*Horizon*") {
    Write-Host "New Horizon agent is installed in $VM"
    }
    else
    {
    Write-Host "New Horizon agent is not installed in $VM" 
    }
}
Disconnect-VIServer $vcenter -Force