When troubleshooting hardware issues, using the power on/off switch yieldsthe most consistent testing procedure. If you suspect a hardware problem,particularly an adapter card problem, using the power switch, rather thanthe CTRL+ALT+DEL key combination or the Reset button, is recommended.
A warm boot, accomplished by pressing the CTRL+ALT+DEL key combination,restarts the computer through the INT19h ROM BIOS routine. This warm-bootprocedure usually does not go through the complete boot process; generally,it skips the power-on self test (POST) to save time. In addition, a warmboot frequently fails to reset all adapters in the computer's adapterslots.
If you use the Reset button to cold boot the computer, it generallyrestarts the boot process, including the POST. However, this procedure doesnot necessarily discontinue power to the motherboard. If the power is notinterrupted, the cold boot may fail to reset all adapters in the computer'sadapter slots.
To ensure that all adapters are properly reset, you should use the powerswitch to turn the computer off. Leaving the power off for ten secondsensures that all the capacitors on the motherboard have time to dischargeand should also give the hard disk drive a chance to stop spinning.
NOTE: Using other reboot methods, such as CTRL+ALT+DEL or the Resetbutton, is acceptable when a hardware problem is not suspected.
If you are using a write-behind cache, ensure the contents of the cachehave been written to the disk before using the power on/off switch. Whenusing SMARTDRV.EXE version 4.0 or later, typing smartdrv /c accomplishes this.