$prtgurl = "http://127.0.0.1:80"
$prtguser= ""
$passhash= ""
$oldcompany = "one"
$newcompany = "two"

## /!\ don't change anything below /!\ ##
$apicall  = "/api/table.json?content=groups&output=json&columns=objid,name"
$devices = "/api/table.json?content=devices&output=json&columns=objid,name"

$apiGroups  = [string]::Format("{0}/api/table.json?content={1}&output=json&columns=objid,name&username={2}&passhash={3}",$prtgurl,"groups",$prtguser,$passhash)
$apiDevices = [string]::Format("{0}/api/table.json?content={1}&output=json&columns=objid,name&username={2}&passhash={3}",$prtgurl,"devices",$prtguser,$passhash)

$Groups  = (Invoke-WebRequest $apiGroups | ConvertFrom-Json)
$Devices = (Invoke-WebRequest $apiDevices | ConvertFrom-Json)

foreach($group in $Groups.groups){
    if($group.name -match $oldcompany){
        $name = $group.name -replace $oldcompany,$newcompany
        Invoke-WebRequest ([string]::Format("{0}/api/rename.htm?id={1}&value={2}&username={3}&passhash={4}", $prtgurl,$group.objid,$name,$prtguser,$passhash)) | Out-Null;
    }
}

foreach($Device in $Devices.devices){
    if($Device.name -match $oldcompany){
        $name = $Device.name -replace $oldcompany, $newcompany
        Invoke-WebRequest ([string]::Format("{0}/api/rename.htm?id={1}&value={2}&username={3}&passhash={4}", $prtgurl,$device.objid,$name,$prtguser,$passhash)) | Out-Null;
    }
}