Operating System: Basics

Operating System of a computer (and most smart devices) is basically a layer of core programs that act as intermediaries between basic computer hardware and the user to make it easy to interact with the gadget/hardware.

Operating System Goals

• Execute User Programs
• Make computer system easy to use
• Use the hardware in an efficient manner

Operating System Components

Includes set of programs that manages interaction with the hardware.

• Kernel: Represents basic functions such as management of memory, processes, files, inputs/outputs and communication functionalities.
• Shell: Allows communication with the operating system via a control language, letting users control the peripherals without knowing the characteristics of the hardware used
• File System: Allows files to be recorded in a tree structure.

Windows, Linux, Sun Solaris and Macintosh are the more popular computer operating systems (OS). But, almost every device with a programmable chip inside (from washing machines to smart phones), has an operating system to control its functionality.

From proprietary systems like Windows and Mac OS X, to open source operating systems like Linux, Unix, and Android, there is plenty of choice out there for users who would like one that suits their requirements.

As devices like smartphones keep evolving to offer greater hardware functionality, every OS is incorporating newer application programming interfaces (APIs). The good thing about is that it provides developers with more creative power to write useful applications (some of which are actually paradigm-shifting).

What Does It Do?

Here are some of the functions carried out by Operating systems:

• Manage Hardware and Software
• Execution of Programs
• User Interface that makes it easy for users to interact with the OS
• Memory Management – Provide adequate memory to the different programs running on the computer
• Scheduling/Multitasking of various tasks
• Interrupt Handling – Capability to stop the current execution and start off a new process.
• Management of Files
• Computer Security & Networking

There are several operating systems that exist out there. Which one you should choose depends on several factors, more importantly being the type of work you intend to do. The computer operating system is indeed the soul of a computer (or any smart device), so choose one for your computer wisely.

Types of Operating Systems

An operating system is responsible for managing the various activities of the computer and also its resources. Most users usually interact with a computer operating system using a Graphical User Interfaces (known as GUI).

Here are the various types of operating systems:

• Single User, Single Task: Preferred for simple, repetitive tasks and is mostly used in Palm handheld PCs.
• Single User, Multi-Task: More popular type, includes Windows and MacOS as well. You can do multiple tasks at the same time – Surf the net, listen to music, etc.
• Multi-User: Requires a lot of resources and maintenance, Unix is one such OS, used by big businesses. In Unix-like operating system, it is possible for multiple users to log in at the same time (uses multi-threading).
• Real-Time Operating Systems (RTOS): Used mainly for managing resources within the computer, and rarely has any user interface. It works like a fully automated assembly line that does not need manual interactions.
• Distributed Operating System: Manages a group of independent computers and makes them appear to be a single computer, distributed computations are carried out on more than one machine, makes it very powerful.

Operating systems simplify human interaction with the computer hardware, making it more user-friendly to use. Companies like Microsoft and Apple have some of the best best OS in the market, there are also some good/popular freeware Operating Systems like Linux.

Regedit File

Regedit file, its structure, format & uses (Windows Registry)

Regedit is basically a utility that allows you to see, search, modify and save the registry database of windows.

Regedit.exe is the built-in Windows registry editor.

It allows users to perform the following functions:

• Creating, manipulating, renaming and deleting registry keys, subkeys, values and value data
• Importing and exporting .REG files, exporting data in the binary hive format
• Loading, manipulating and unloading registry hive format files (Windows NT-based systems only)
• Setting permissions based on ACLs (Windows NT-based systems only)
• Bookmarking user-selected registry keys as Favorites
• Finding particular strings in key names, value names and value data
• Remotely editing the registry on another networked computer

Although regedit.exe can be used to manually edit the Windows registry, these tools usually do not expose some of registry’s metadata such as the last modified date.

How is the Registry Organized?
The windows registry is organized into keys and sub-keys, with each key containing a value-entry.

The five principal keys include:

1. HKEY_LOCAL_MACHINE
2. HKEY_CURRENT_USER
3. HKEY_ USERS
4. HKEY_CLASSES_ROOT
5. HKEY_CURRENT_CONFIG

Warning: Because the regedit utility allows you to change configuration of the operating system, you have to be careful while using it. Any careless change in the registry could cause the computer to stop working normally.

That’s why usually only the installer programs perform changes to the registry database during installation/configuration and removal.

If you want to manually edit certain keys, its better to take a backup of the registry before proceeding with the changes.