(Wind River Systems, Inc., 2015 para. It starts in the operating system). Computers can generally be classified according to their size and capabilities as follows: personal computer; small computer for singer user. Desktop model: computer designed to sit comfortably on a desk. Laptop: Extremely lightweight personal computer. Laptop: small laptop. (https://.cs.cmu.edu/~fgandon/lecture/uk1999/computers_types). To secure different devices, security software must match the capabilities of the hardware of the device on which it will be installed. The first security measure a user can take is to secure access to their computer. If you want to prevent people from using applications on your personal computer or want to keep information secure, security measures should be taken..