A stable operating system is essential. The most common operating systems are as follows:

	Unix
	Dos
	Windows 9X/ME
	Windows NT/2000/XP

UNIX/LINUX
Very Reliable. Good for network applications, but complex to use. Graphical interface optional. Steep learning curve, but improvements are being made to make LINUX more friendly to the common user.

DOS
Reliable. Non-graphical interface. Does not require much CPU resources. Can be very fast. Minimal operating system. not multi-tasking.

WINDOWS 9X/ME
Windows 9X/ME are intended for the home user and it is not recommended for business applications. Very unstable. Most frequent crashes and downtime. Excellent graphics. Very CPU intensive. Uses excessive computer power to maintain operating system. Point and click interface. Compatible with most software.

WINDOWS NT/2000/XP - Recommended
Windows NT/2000/XP was developed for business applications. Workstation and server versions available. Very stable. Excellent graphics. Strong network capabilities. Uses most computer memory to maintain operating system. Point and click interface.