Background: In Windows 2000 and later the threads in the System Idle Process are also used to implement CPU power saving. The exact power saving scheme depends on the operating system version and on the hardware and firmware capabilities of the system in question. For instance, on x86 processors under Windows 2000, the idle thread will run a loop of halt instructions, which causes the CPU to turn off many internal components until an interrupt request arrives. Later versions of Windows implement more complex CPU power saving methods. On these systems the idle thread will call routines in the Hardware Abstraction Layer to reduce CPU clock speed or to implement other power-saving mechanisms.

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In which computer the idle thread will run a loop of   halt instructions, office computer or home computer?
Answer: office computer

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In which computer the idle thread will not run a   loop of halt instructions, office computer or home   computer?
Answer: home computer

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In John's home computer the idle thread will run or   will not run a loop of halt instructios?
Answer: will not run

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In John's office computer the idle thread will run   or will not run a loop of halt instructios?
Answer: will run

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In which computer CPU will turn off many internal   components, office computer or home computer?
Answer: office computer

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In which computer CPU will not turn off many   internal components, office computer or home computer?
Answer: home computer

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In John's office computer CPU will turn off or will   not turn off many internal components?
Answer: will turn off

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: In John's home computer CPU will turn off or will not turn off many internal components?
Answer: will not turn off

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: Does John's home computer have less complex or more complex CPU power saving methods?
Answer: more complex

Situation: John spends most of his time on computers. While at work his work computer does not need modern 
capabilities. So, he still uses Windows 2000 at his office computer. At home it's a complete different ball game. He plays so much computer games at home that he needs a better computer. In his home computer he 
installed the latest version of Windows. Now, there is no lag in his system.

Question: Does John's office computer have less complex or more complex CPU power saving methods?
Answer: less complex