I've recently purchased a PC for my retail business. I am very concerned about security. The computer should make information retrieval and storage faster and simpler than a paper system. With the proprietary nature of business data, you have started in a wise direction by being concerned about security. There are two major types of protection, those regarding the data and those concerned with the physical asset.
Many companies opt for combinations of passwords, encryption and backups to secure information.
The goals of each method are different. Passwords are used to limit access to the operating system, and programs on the computer. Some operating systems require a password to access the machine, while others appear to require it, but the log on process can be bypassed with the escape key. Many programs allow access to be limited by the use of a password when the program is run, or when specific activities are performed within a program. With either type of password, several concepts are important.