Get-InstalledDotNetFramework.ps1

$ReleaseKey = Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full\' |  Get-ItemPropertyValue -Name Release

if ($ReleaseKey -ge 528040) {
    return "4.8 or later";
}

if ($ReleaseKey -ge 461808) {
    return "4.7.2";
}

if ($ReleaseKey -ge 461308) {
    return "4.7.1";
}

if ($ReleaseKey -ge 460798){
    return "4.7";
}

if ($ReleaseKey -ge 394802) {
    return "4.6.2";
}

if ($ReleaseKey -ge 394254) {
    return "4.6.1";
}

if ($ReleaseKey -ge 393295) {
    return "4.6";
}

if ($ReleaseKey -ge 379893) {
    return "4.5.2";
}

if ($ReleaseKey -ge 378675) {
    return "4.5.1";
}

if ($ReleaseKey -ge 378389) {
    return "4.5";
}

# This code should never execute. A non-null release key should mean
# that 4.5 or later is installed.
return "No 4.5 or later version detected";