diff --git a/profile.d/SystemName.class.ps1 b/profile.d/SystemName.class.ps1
index 022340f..8ce740f 100644
--- a/profile.d/SystemName.class.ps1
+++ b/profile.d/SystemName.class.ps1
@@ -18,6 +18,7 @@ class SystemName { #: System.Management.Automation.IValidateSetValuesGenerator {
         }
         $possibleValues.out = $possibleValues.out |
             Select-Object -Unique |
+            Where-Object { $_ } |
             Sort-Object {
                 $local:sortName = "zz_$_";
                 if( $_ -in $possibleValues.Exist -and $_ -in $possibleValues.Current ) { $sortName[0] = "a" }
diff --git a/sys.Linux/Set-EnvVariable.ps1 b/sys.Linux/Set-EnvVariable.ps1
new file mode 100644
index 0000000..a51daa7
--- /dev/null
+++ b/sys.Linux/Set-EnvVariable.ps1
@@ -0,0 +1,6 @@
+[CmdletBinding()]param(
+  [string]$Name,
+  [object]$Value
+)
+
+Set-Item -Path (Join-Path "env:" $Name) -Value $Value
diff --git a/sys.Windows/Set-EnvVariable.ps1 b/sys.Windows/Set-EnvVariable.ps1
new file mode 100644
index 0000000..5de891d
--- /dev/null
+++ b/sys.Windows/Set-EnvVariable.ps1
@@ -0,0 +1,11 @@
+[CmdletBinding()]param(
+  [string]$Name,
+  [object]$Value,
+  [ValidateSet('User','Machine')]
+  [string]$Persist
+)
+
+Set-Item -Path (Join-Path "env:" $Name) -Value $Value
+if( $Persist ) {
+    [environment]::setEnvironmentVariable($Name, $Value, $Persist)
+}
\ No newline at end of file