1. Early versions of UNIX were available only with a command-driven interface. 

In more recent years, graphical user interfaces have become popular. Explain 

in your own words why these GUIs made an impact on the popularity of this 

operating system.

2. Assume that you are a systems administrator. Explain why you might want 

to change the permissions on some of your directories to make them invisible 

to users.

3. Administrators sometimes find that when they deploy Windows in 

a multilingual environment, some languages require more hard-disk 

storage space than others. Why might that be the case? Explain your answer 

and give an example of one languages that could be expected to require 

more space.

4. Windows features Kerberos authentication. Describe the role of the ticket 

granting ticket to authenticate users for network access.

5. Identify at least five major types of threats to systems running Windows and 

the policies that system administrators must take to protect the system from 

unauthorized access. Compare the practical problems when balancing the need 

for accessibility with the need to restrict access, and suggest the first action you 

would take to secure a Windows computer or network if you managed one.

6. Examine the following list of permissions for four items included in a directory 

listing. Identify if it is a file, directory, or other. Specify the access allowed to 

three categories: world, user, and group. Identify any category of users who are 

denied any access to all of these files.

 a. -rwx—r-x

 b. drwx—rwx

 c. d–x—r-x

 d. prwx——-

7. Linux uses an LRU algorithm to manage memory. Suppose there is another 

page replacement algorithm called not frequently used (NFU) that gives 

each page its own counter that is incremented with each clock cycle. In this 

way, each counter tracks the frequency of page use, and the page with the 

lowest counter is swapped out when paging is necessary. In your opinion, 

how do these two algorithms (LRU and NFU) compare? Explain which 

one would work best under normal use, and define how you perceive 

“normal use.”

8. Compare and contrast Android and the Linux operating systems.

9. Compare and contrast the Android and Windows operating systems.

10. The role of the Linux kernel is crucial to the Android operating system. 

Explain in your own words why this is so.