Abstract: An instant-on instrument system is achieved by having the operating system boot completely when power is first applied to the instrument system, but when the system is still in the off mode. The OS brings the instrument system to the point where all internal checks have been accomplished but does not turn on anything externally detectable functions, such as the display, the display backlight and the fan. Once the OS has booted, the hard drive is stopped, the clock rate is reduced, power is removed from any measurement PC cards. At this point the instrument system is essentially in a “sleep” mode. When a user turns the instrument system on, the clock rate picks up, and all other functions come alive for the duration of the testing cycle. When the user turns the instrument system off, the system reboots and then returns to the sleep mode once again.