If your device is infected by a virus or accessed by a criminal, your data may be damaged, deleted, stolen, or held to ransom. This means you will not be able to access it. Therefore back up your most important data to somewhere separate from your computer such as a secure external hard drive or storage system based in the Cloud.
You should also ensure you regularly test your back-ups and, if you are saving confidential information off-site e.g. in the Cloud, follow all appropriate data protection measures and government standards and guidance that relate to health and social care organisations.
The National Cyber Security Centre have good guides for small businesses on how to back up your data. They split this into 5 tips.