1. 5.0 : Windows Operating System
Part 2 : OS Maintenance

2. Learning Outcomes
5.2 Understanding OS Maintenance Explain function of patches in operating system Differentiate between patches for operating system and application software Determine the OS system version and revision

3. What is Patches?
A patch is a piece of program code that can correct a problem or enhance the functionality of an application program or OS.

4. Why and When to Apply Patches
Once an OS or application is installed, it is important to keep it up to date with the latest patches.
They are usually provided by the manufacturer to repair a known vulnerability or reported problem.

5. Why and When to Apply Patches
Computers should be continually updated with the latest patches unless there is a good reason not to do so
Sometimes patches may negatively impact the operation of another system feature
The impact of the patch should be clearly understood before it is applied.
This information can usually be found on the software manufacturer's web site.

6. Applying OS Patches
Patches to operating systems can be installed in different ways, depending on the OS and the needs of the user.
Options for downloading and installing updates include:
a. Automatic Installation
b. Prompt for permission
c. Manual

7. Option for Installing Updates: Automatic Installation
The OS can be configured to connect to the manufacturer's web site, download and install minor updates without any user intervention.
Updates can be scheduled to occur
during times when the
computer is on, but not in use.

8. Option for Installing Updates: Prompt for Permission
Some users wish to have control over which patches are applied. This is often the choice of users who understand what impact a patch may have on system performance.
The system can be configured to notify the end-user when a patch is available. The user must then decide if the patch should be downloaded and installed.

9. Option for Installing Updates: Manual
Updates that require major pieces of code to be replaced on a system should be run manually.
These major updates are often called service packs and are designed to correct problems with an application or OS, and sometimes to add functionality.
These service packs usually require the end user to manually connect to a web site, download and install the update.
They may also be installed from a CD that can be obtained from the manufacturer.

10. Application Patches and Updates
Applications also require patches and updates.
Patches are usually released by the manufacturer, to repair a detected vulnerability in the application that could lead to undesirable behavior.

11. Application Patches and Updates
Browsers and office software such as word processors, spreadsheet and database applications are common targets for network attacks.
These applications require updates to correct the code that may allow the attack to succeed.
The manufacturer may also develop updates that can improve product functionality, at no additional cost.

12. File System
A file system is a part of the OS that determines how files are named, stored & organized on a volume.
A file system manages files & folders & the information needed to locate & access these items by local & remote users.

13. FAT & NTFS
FATxx is an old file system that is simple, well-documented, readable from a large number of OSs, and supported by a wide range of tools.
NTFS is a newer file system that is feature-rich, proprietary, undocumented at the raw bytes level & subject to change - even within Service Packs of the same OS version. 
NTFS - security features deep within the file system itself, NTFS allows you to gain the maximum benefits for the needs of today’s enterprise business environments such as increased security, more robust and reliable performance, as well as a design for greater storage growth, features not found in FAT.

14. Advantages of FAT
The FAT file system is best for drives and/or partitions under approximately 200 MB, because FAT starts out with very little overhead.

15. Disadvantages of FAT
Preferably, when using drives or partitions of over 200 MB the FAT file system should not be used. This is because as the size of the volume increases, performance with FAT will quickly decrease. It is not possible to set permissions on files that are FAT partitions.

16. Advantages of NTFS
NTFS is best for use on volumes of about 400 MB or more. This is because performance does not degrade under NTFS, as it does under FAT, with larger volume sizes. The recoverability designed into NTFS is such that a user should never have to run any sort of disk repair utility on an NTFS partition.

17. Disadvantages of NTFS
It is not recommended to use NTFS on a volume that is smaller than approximately 400 MB, because of the amount of space overhead involved in NTFS. Currently, there is no file encryption built into NTFS. Therefore, someone can boot under MS-DOS, or another operating system, and use a low-level disk editing utility to view data stored on an NTFS volume.

18. Summary
An OS and application software must be kept up to date with the latest revisions, upgrades or patches.
Services pack are major updates to an OS or software application
Application software can also require patches and updates to repair a detected vulnerability in the application
Application patches are generally found through the manufacturer website.