Problem analysis:

It can only be used on three computers, but it is estimated that it cannot be activated in the past year or two.

:

The Computer Level 2 Examination is one of the four levels of the National Computer Rank Examination (NCRE), which tests basic computer knowledge and the use of an advanced Basic skills in computer language programming and computer debugging. The computer level two examination adopts the form of national unified propositions and unified examinations.

(Data source: Baidu Encyclopedia: Computer Level 2 Examination)