Windows 11 - if you are running an older operating system, you need to upgrade.
If you computer will not run Windows 11 operating system, then you will need to get a new computer. I recommend Dell and Lenovo computers.
AntiVirus
Microsoft Defender Antivirus is preinstalled on Windows 11.
Another option is BitDefender - https://Bitdefender.com - starting at $29.99 and up.
Spyware/Malware removal
Malwarebytes.org http://malwarebytes.com (free version)
Backup
Microsoft One Drive - is a great option if your paying for Office 365.
Carbonite (Basic Version) $56.99 a year https://www.carbonite.com/
Built in Windows 11 backup software (requires external USB hard drive)