Throughout my days as a PHP Programmer and a beginner at C# programming I've always wondered of the best way to generate unique serials such as how Microsoft Office and Microsoft operating systems do.Does anyone have a good guide to how to handle this, Like what are the important factors in generating the unique serial, prevent duplicates etc. small example on how to create / verify them.Here is the RFC im tlaking about: http://tools.ietf.org/html/rfc1982Any advice / guides / samples are appreciated 
Regards
Regards