Dim FolderPath As String = "C:\Test" 'Specify the folder here
Dim UserAccount As String = "mydomain\Someuser" 'Specify the user here
Dim FolderInfo As IO.DirectoryInfo = New IO.DirectoryInfo(FolderPath)
Dim FolderAcl As New DirectorySecurity
FolderAcl.AddAccessRule(New FileSystemAccessRule(UserAccount, FileSystemRights.ReadAndExecute Or FileSystemRights.Write, InheritanceFlags.ContainerInherit Or InheritanceFlags.ObjectInherit, PropagationFlags.None, AccessControlType.Allow))
'FolderAcl.SetAccessRuleProtection(True, False) 'uncomment to remove existing permissions
FolderInfo.SetAccessControl(FolderAcl)