You don't have to renew your subscription to Norton Antivirus. There is no shortage of good free antivirus software problems. I'll get back to that later. Do not buy another Windows license. Experts have estimated that up to 42% of copies of Windows which were detected as not genuine by Windows Genuine Advantage (WGA) validation were in fact genuine. You can use Microsoft's WGA support center to get more details on how to validate your copy of Windows. Even in cases in which Microsoft confirms that you do not have a valid license key, they will give you another one if you just provide details of how you got the first copy. In addition, even without a valid license key, you can still get all of the security patches. However, you will not be able to download other Microsoft software, such as Windows Defender or .NET Framework. So, I strongly recommend not to purchase another copy of Windows. If you want, I can also tell you how to stop Windows from constantly nagging you about your copy of Windows.
Going back to your antivirus question. You don't need to renew your subscription with Norton Antivirus. Norton's products are notorious for slowing down computer because they use a lot of resources and worse they are also expensive. Instead, consider using a free antivirus like: AVG, Antivir and Avast. These 3 are the most popular free antivirus programs available. The simplest to setup and use is AVG. Antivir has some advance settings which requires some advanced computer knowledge, while Avast requires you to register every 4 months to continue using their product. You can download any one of these at:
http://www.filehippo.com/software/antivirus/
If you are adamant about using Norton Antivirus, Google's Pack offers a special Norton Antivirus version with a free 6 months of updates. After 6 months, you have to purchase a license to continue using it. You can download it at:
http://pack.google.com/intl/en/pack_installer.html?hl=en&gl=us
If you have anymore questions or need help setting up either the antivirus or the Windows operating system, just send me an e-mail. Good luck.