Frequently Asked Questions

Windows 8.1 and Windows 10

The product key is located inside the product packaging, on the receipt or confirmation page for a digital purchase or in a confirmation e-mail that shows you purchased Windows. If you purchased a digital copy from Microsoft Store, you can locate your product key in your Account under Digital Content.

The product key is located inside the box that the Windows DVD came in, on the DVD, on the receipt or confirmation page for a digital purchase or in a confirmation e-mail that shows you purchased Windows. If you purchased a digital copy from Microsoft Store, you can locate your product key in your Account under Digital Content.

Your product key is located on the receipt page when you purchase or in the Order History section of the WebStore from which you ordered the software.

Devices Pre-Installed with Windows

Before using operating system copies from this site for install, re-install or recovery on devices with pre-installed operating systems, see your device manufacturer or reseller for the customized drivers and applications specific to your machine. Using operating systems copied from this site for install, re-install or recovery may void your support agreement with your manufacturer or reseller. Any drivers or programs that were installed by the device manufacturer or reseller may be removed during installation.

Windows 8.1 & 10: The product key may be embedded on the motherboard or may be on the Certificate of Authenticity sticker on the bottom of the device.

Windows 7: For devices that came with Windows 7 pre-installed, the product key may be on the Certificate of Authenticity sticker on the bottom of the device.

For more information about Windows product keys and genuine Microsoft products, see What is a product key and How to Tell site.

The most common issue is the use of a product key for a product not currently supported by the site such as an Upgrade key, an MSDN key, product keys for pre-installed media or an Enterprise edition key. For access to MSDN products or Enterprise edition visit the MSDN Portal or the Volume Licensing Service Center. Upgrades and pre-installed media are not currently supported by the tools on the site.

If you believe you have a valid product key and are still receiving an error, please contact Support.

Not all “system builder” products for Windows 7 are currently available on the site. We are working to add more, but for now, we suggest you contact Support.

Yes, but you’ll need your product key. Go to the Academic Products download page and select the version of Windows to begin.

The media creation tool (Download Tool Now button) will not run on a Mac device. You can still download an ISO file with one of these options: Windows 8.1 or Windows 10. This will give you a web-based download option that should run on most browsers.

Before using operating system copies from this site for install, re-install or recovery on devices with pre-installed operating systems, see your device manufacturer or reseller for the customized drivers and applications specific to your machine. Using operating systems copied from this site for install, re-install or recovery may void your support agreement with your manufacturer or reseller. Any drivers or programs that were installed by the device manufacturer or reseller may be removed during installation.

You can download an ISO file copy of Windows to use with a non-Windows device. Follow these links for Windows 10, Windows 8.1 or Windows 7 ISO download options best for non-Windows devices.

The terms 32-bit and 64-bit refer to the way a computer’s processor (also called a CPU) handles information. The 64-bit version of Windows handles large amounts of random access memory (RAM) more effectively than a 32-bit system. Not all devices can run the 64-bit versions of Windows.

If you have a Windows operating system installed, open File Explorer or This PC.

1. Right click on This PC or Computer in the navigation pane and select Properties.
2. In the System information screen, find the System type entry. This will indicate what type of processor your device has.

If you do not have an operating system installed, you should refer to the documentation that came with the device. Most device and processor manufacturers also provide information regarding processor capabilities on their websites.

For other options and more information on Windows 7 visit the Windows 7 32-bit and 64-bit FAQ page or download and run the free Windows 7 Upgrade Advisor.

After you’ve created the installation media, do one of the following to install Windows:

• Connect the USB flash drive to the PC where you want to install Windows, browse to it in File Explorer, and then open the setup.exe file. Follow the instructions in setup.
• If your PC is set up to boot from a USB drive, connect the USB flash drive to the PC where you want to install Windows, restart (reboot) it, and then follow the instructions in setup.
• If your PC is set up to boot from the DVD drive, insert the DVD into your PC, restart (reboot) it, and then follow the instructions in setup.

You can use the ISO file to create bootable media for installation or recovery. You can also install Windows on your current device by opening the ISO file, selecting the Setup and following the instructions.

To create bootable media such as a bootable USB drive or DVD, you will need an ISO burning or mounting software. We recommend always using a blank USB or blank DVD because contents may be deleted when creating a bootable image.

If you are creating media from a Windows 8.1 machine, you can also right click the ISO file and select either Mount to mount the image to the current device or a USB drive or select Burn disc image to burn a DVD (this requires a DVD burner and a blank DVD).

If you are creating a DVD from a Windows 7 machine, you can right click the ISO file and select Burn disc image or Open with, then Windows Disc Image Burner to burn a DVD (this requires a DVD burner and a blank DVD). This DVD can be used to install media and is bootable.

If you are creating media from a Windows 7 machine, you may need to use a separate burning or mounting software such as the Windows 7 USB/DVD Download Tool. Before using this tool, be sure to read the Information and Instructions. You can also right click the ISO file and select Burn disc image to burn a DVD (this requires a DVD burner and a blank DVD).

You can also visit Microsoft Community to research other options.

To use the bootable media, make sure the device you will be installing on is set to boot from a USB or DVD. Then connect the USB or insert the DVD, restart (reboot) the device and then follow the instructions in setup.

Windows 8.x and Windows 10 Pre-installed: You can download and use media from this site on your device and it will install correctly. In most cases you will not be asked for a product key during installation, the product key is included on the motherboard. However, after installation, the device will NOT contain the specialized drivers and software that came pre-installed from your manufacturer. *If you are prompted for a product key during installation, refer to How do I find my Windows product key? question above.

Windows 7 Pre-installed: We strongly recommend you contact the device manufacturer for support.

If you are looking for MSDN products or Enterprise editions visit the MSDN Portal or the Volume Licensing Service Center.

The media from this site can be used to create bootable USB drives and DVDs which will allow you to access recovery tools.

What is Operating System? Types of OS, Features and Examples

What is an Operating System?

An Operating System (OS) is a software that acts as an interface between computer hardware components and the user. Every computer system must have at least one operating system to run other programs. Applications like Browsers, MS Office, Notepad Games, etc., need some environment to run and perform its tasks.

The OS helps you to communicate with the computer without knowing how to speak the computer’s language. It is not possible for the user to use any computer or mobile device without having an operating system. Introduction to Operating System

History Of OS

• Operating systems were first developed in the late 1950s to manage tape storage
• The General Motors Research Lab implemented the first OS in the early 1950s for their IBM 701
• In the mid-1960s, operating systems started to use disks
• In the late 1960s, the first version of the Unix OS was developed
• The first OS built by Microsoft was DOS. It was built in 1981 by purchasing the 86-DOS software from a Seattle company
• The present-day popular OS Windows first came to existence in 1985 when a GUI was created and paired with MS-DOS.

Examples of Operating System with Market Share

Following are the examples of Operating System with the latest Market Share

OS Name	Share
Windows	40.34
Android	37.95
iOS	15.44
Mac OS	4.34
Linux	0.95
Chrome OS	0.14
Windows Phone OS	0.06

Types of Operating System (OS)

Following are the popular types of Operating System:

• Batch Operating System
• Multitasking/Time Sharing OS
• Multiprocessing OS
• Real Time OS
• Distributed OS
• Network OS
• Mobile OS

Batch Operating System

Some computer processes are very lengthy and time-consuming. To speed the same process, a job with a similar type of needs are batched together and run as a group.

The user of a batch operating system never directly interacts with the computer. In this type of OS, every user prepares his or her job on an offline device like a punch card and submit it to the computer operator.

Multi-Tasking/Time-sharing Operating systems

Time-sharing operating system enables people located at a different terminal(shell) to use a single computer system at the same time. The processor time (CPU) which is shared among multiple users is termed as time sharing.

Real time OS

A real time operating system time interval to process and respond to inputs is very small. Examples: Military Software Systems, Space Software Systems are the Real time OS example.

Distributed Operating System

Distributed systems use many processors located in different machines to provide very fast computation to its users.

Network Operating System

Network Operating System runs on a server. It provides the capability to serve to manage data, user, groups, security, application, and other networking functions.

Mobile OS

Mobile operating systems are those OS which is especially that are designed to power smartphones, tablets, and wearables devices.

Some most famous mobile operating systems are Android and iOS, but others include BlackBerry, Web, and watchOS.

Functions of Operating System

Below are the main functions of Operating System: Functions of Operating System

In an operating system software performs each of the function:

1. Process management:- Process management helps OS to create and delete processes. It also provides mechanisms for synchronization and communication among processes.

1. Memory management:- Memory management module performs the task of allocation and de-allocation of memory space to programs in need of this resources.

1. File management:- It manages all the file-related activities such as organization storage, retrieval, naming, sharing, and protection of files.

1. Device Management: Device management keeps tracks of all devices. This module also responsible for this task is known as the I/O controller. It also performs the task of allocation and de-allocation of the devices.

1. I/O System Management: One of the main objects of any OS is to hide the peculiarities of that hardware devices from the user.

1. Secondary-Storage Management: Systems have several levels of storage which includes primary storage, secondary storage, and cache storage. Instructions and data must be stored in primary storage or cache so that a running program can reference it.

1. Security:- Security module protects the data and information of a computer system against malware threat and authorized access.

1. Command interpretation: This module is interpreting commands given by the and acting system resources to process that commands.

1. Networking: A distributed system is a group of processors which do not share memory, hardware devices, or a clock. The processors communicate with one another through the network.

1. Job accounting: Keeping track of time & resource used by various job and users.

1. Communication management: Coordination and assignment of compilers, interpreters, and another software resource of the various users of the computer systems.

Features of Operating System (OS)

Here is a list important features of OS:

• Protected and supervisor mode
• Allows disk access and file systems Device drivers Networking Security
• Program Execution
• Memory management Virtual Memory Multitasking
• Handling I/O operations
• Manipulation of the file system
• Error Detection and handling
• Resource allocation
• Information and Resource Protection

Advantage of using Operating System

• Allows you to hide details of hardware by creating an abstraction
• Easy to use with a GUI
• Offers an environment in which a user may execute programs/applications
• The operating system must make sure that the computer system convenient to use
• Operating System acts as an intermediary among applications and the hardware components
• It provides the computer system resources with easy to use format
• Acts as an intermediator between all hardware’s and software’s of the system

Disadvantages of using Operating System

• If any issue occurs in OS, you may lose all the contents which have been stored in your system
• Operating system’s software is quite expensive for small size organization which adds burden on them. Example Windows
• It is never entirely secure as a threat can occur at any time

What is a Kernel?

The kernel is the central component of a computer operating systems. The only job performed by the kernel is to the manage the communication between the software and the hardware. A Kernel is at the nucleus of a computer. It makes the communication between the hardware and software possible. While the Kernel is the innermost part of an operating system, a shell is the outermost one.

Features of Kennel

• Low-level scheduling of processes
• Inter-process communication
• Process synchronization
• Context switching

Types of Kernels

There are many types of kernels that exists, but among them, the two most popular kernels are:

1.Monolithic

A monolithic kernel is a single code or block of the program. It provides all the required services offered by the operating system. It is a simplistic design which creates a distinct communication layer between the hardware and software.

2. Microkernels

Microkernel manages all system resources. In this type of kernel, services are implemented in different address space. The user services are stored in user address space, and kernel services are stored under kernel address space. So, it helps to reduce the size of both the kernel and operating system.