I've been got by Think Point

It looks fine now but you currently don't have an antivirus installed.

Please install Avira antivirus otherwise you won't be protected.

1) Antivir PersonalEditionClassic
-Free anti-virus software for Windows.
-Detects and removes more than 50,000 viruses. Free support.

It is strongly recommended that you run only one antivirus program at a time. Having more than one antivirus program active in memory uses additional resources and can result in program conflicts and false virus alerts.

Thanks Belahzur! I just installed Avira Antivirus - it told me I had to turn off Windows defender so I did that. Hopefully everything is good now - really appreciate all the help you and this site provide.