will CS Cart run on windows 2012 server having issues with SEO and auctions add on
George
should i use ubuntu instead of windows server 2012
No one can tell you what type of server to run. It depends on your business needs and what else you might be doing on that server. If all you're doing is hosting your store, then I'd recommend just using a small VPS running standard Linux. It will be worth your while to purchase “Managed hosting” so you can get reasonable support if you need it.
Generally people only run a Windoz server if they are also running Exchange or Sharepoint and need those specific services.