at version 1.0.1 this looks like a VERY young product apparently it was still in beta in 2017 from the article at https://nano-av.com/nano-antivirus-v-0-30-beta-was-offered-for-the-opswat-certification/

There is a wikipedia article on this https://en.wikipedia.org/wiki/Talk:NANO_Antivirus

I find the entry a little suspicious for example there is a statement

"NANO Security Ltd is included in the Microsoft list of reputable security companies that provide consumer security software compatible with Microsoft Windows."

IF that is a true statement why is there no reference link to this "Microsoft list"

I do see conflicting information on their website in some places and in system requirements in information panel above it says only Windows 7 or better but on

https://nano-av.com/product/nano-antivirus-pro-for-business/

It has:

"System requirements:
OS
Microsoft Windows 10 (32-bit and 64-bit)
Microsoft Windows 8.1 (32-bit and 64-bit)
Microsoft Windows 8 (32-bit and 64-bit)
Microsoft Windows 7 (32-bit and 64-bit)
Microsoft Windows Vista (32-bit and 64-bit)
Microsoft Windows Server 2003 SP1 and higher (32-bit and 64-bit)
Microsoft Windows XP SP3 (32-bit and 64-bit)
Other
Internet connection available
Administrator rights"

Looking around the website it talks of commendations and awards and recomendations from all sorts of industry names but oddly for a commercial website it does not include LINKS to those organisations glowing articles which would serve multiple functions, it would substantiate their claims... and it would significantly improve their search engine ranking too!

just using google I came up with:

https://www.av-comparatives.org/products/nano-antivirus-pro/

Apparently according to one reviewer/affiliate the real installer requires a download of around 700MB which means it will unpack to significantly more and you'll likely find the small download from here is just a downloader tool that then downloads the real installer from their server.

Just checked yep it procedes to download a 681MB installer... it pretends it's looking for an updated installer as if it was an installer itself which it is not. It always was and is a downloader. I would suggest you make sure that your system drive has at least 2 GigaBytes spare space to unpack the downloaded 681Mbyte installer and then to copy those unpacked files to their final installed location. And if you are on a slow connection be prepared to need to be patient.

Installed a few months ago, the program takes up to 1 gigabyte of process! Abnormally, I immediately uninstalled it.

Why should I take the risk of installing an unknown anti-virus with only 200 days of license if there are many free and good AVs like Avast, Avira, AVG, Panda, etc., not to forget the Win10-pre-installed Microsoft Defender which in the meantime is also very good.

Just did a search for antivirus ratings on PC Mag, CNet, Consumer Reports, and a couple of other not well known places and 'Nano' never appeared. There are many places that seem to have rated them, but, imo, are questionable. This may be a good program but without being picked up by the mainstream test centers I am leery of it's effectiveness.

Never heard of the antivirus, thanks but I'll keep using what I trust. Thanks!