Query Registry of a list of Hosts

I am trying got query a key value in a few remote hosts on our domain. I wrote this:

$computers = Get-Content "E:\temp\list.txt"
    foreach($computer in $computers){
        $objReg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $Computer)
        $objRegKey= $objReg.OpenSubKey("\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion" )
        $objRegkey.GetValueNames("ReleaseId")
}

…but get error:

You cannot call a method on a null-valued expression.
At line:5 char:9
+         $objRegkey.GetValueNames("ReleaseId")

There’s a value there so not sure why it errors. Can someone help please?

thank you

$objRegKey = $objReg.OpenSubKey('SOFTWARE\Microsoft\Windows NT\CurrentVersion' )
$objRegKey.GetValue('ReleaseId')

Thanks Olaf, perfect.