Hi:
I'm not sure what you mean about a "single cover".
I think you are referring to a 1-PC license?
Kaspersky licensing can be very complicated, as they offer multiple different products with separate licensing, a range of 1-PC to up to at least 5-devices per license (for their multi-device, consumer product), AND both "managed subscriptions" and standalone licenses (via boxed products).
The "easiest" and "safest" way to renew, especially for a managed subscription, is to renew through the built-in renewal in the product GUI. That will -- by default -- typically include AUTO-RENEWAL. If you do not want that, you have to opt out after you buy (cumbserome, but not impossible). KL usually offers a discount for current customers, but it may not be the cheapest price. They also offer promotions from time to time. And there are 2-year (and perhaps 3-year) licenses, too.
Some users prefer the subscription because it requires the least work for them, and their license is less likely to expire by mistake.
The "better" way to renew, especially if you do NOT want auto-renewal, is to buy a standalone license in a "box". There is no longer a CD in the box, but there is a card with an activation code.
These are available online from good retailers, and in brick/mortar computer stores.
This will NOT come with auto-renewal, so many savvy users (myself included) use this method. The price is often better and a bit cheaper.
Upgrades are free during your valid license period.
The current license policy is"-1 and +3", so (for example) a 2017 license is good for the following versions: 2016 2017 2018 2019 2020
IF you can find a VALID, LEGAL license for version 2016 from a credible source, it may be cheaper than one for version 2017, but it will work just fine for 2017.
HOWEVER, the BIG caveat is that you must purchase your license from a reputable source and for your geographic region. KL is VERY stringent about piracy and that includes not buying a license (for example) in the US and then activating it (for example) in China, or vice versa. Forget eBay. Be very wary of other online sources, even Amazon (do NOT use the Marketplace).
And a KAV license does not work for KIS, nor vice versa. So be sure to buy the correct license for the correct product.
So, there is no one, single, best answer to your question.
It depends foremost on whether you want managed subscription.
Then, if you opt for buying a license by any means or from any source other than directly from Kaspersky, be VERY careful where you buy it.
HTH,
MM
