I want to amplify MoxiMomma's and simrick's impression of Spybot S&D as not being your best choice in Virus protection.
Spybot uses the Hosts file (or it used to) to mitigate some malware. If you don't have any special needs for a non-standard Hosts file, then when you uninstall Spybot to replace it with a different AV product, you should also reset the hosts file
# Copyright (c) Microsoft Corp.
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
# For example:
# 126.96.36.199 rhino.acme.com # source server
# 188.8.131.52 x.acme.com # x client host
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
See: How can I reset the Hosts file back to the default?
Don't worry about the Windows versions - the Hosts file is standard. The only difference being the addition of IPv6 and letting the DNS handle the localhost name resolution.
There are ample choices available that are superior, or at least less problematic for Windows, to Spybot.
It comes down a preference really. I'm comfortable with Microsoft's Defender, but have used others in the past.
AV products used by other members include:
Malwarebytes Free (manual scan as a 2nd line of defense)
--> Malwarebytes Premium is real time protection but is not free,
Super Anti-Spyware Free
But there are more (some might not offer free real-time protection):
Partners in consumer antivirus software for Windows - Microsoft Windows
I've recently been looking at Bitdefender Free.
Bitdefender is always in the top ranks along with Kaspersky (no free product that I know of).
The free version of Bitdefender is 2014 - it's unclear that it is compatible with Win10. There is conflicting information on the Bitdefender 2016 page - probable just an oversight while they were updating the software.
A buy Bitdefender 2016 pop-up has this:
So, I have to ask myself ... what about 2014 - the free version? I have not tried it, so I can't answer my own question.