How to Format your Computer by your self

-First you must save your personal/important files in a partion !

(this step is optional for who want to save some files!)

1) how to partition your hard disk : 
🌚in your search bar (in start menu)                                               

🌚write " executer " then press 'enter' , it will appear a window like this

🌚Open the Disk Management console by typing diskmgmt.msc and 'enter'

🌚right click on the partition tha you want to cut her size to a new partition ;

The Specify Volume Size page specifies the minimum and maximum size for the volume in megabytes and lets you size the volume within these limits. Size the partition in megabytes using the Simple Volume Size field and then click Next. 

🌚On the Assign Drive Letter Or Path page, specify whether you want to assign a drive letter or path and then click Next. The available options are as follows: 

Assign The Following Drive Letter Select an available drive letter in the selection list provided. By default, Windows 7 selects the lowest available drive letter and excludes reserved drive letters as well as those assigned to local disks or network drives. 
Mount In The Following Empty NTFS Folder Choose this option to mount the partition in an empty NTFS folder. You must then type the path to an existing folder or click Browse to search for or create a folder to use. 
Do Not Assign A Drive Letter Or Drive Path Choose this option if you want to create the partition without assigning a drive letter or path. Later, if you want the partition to be available for storage, you can assign a drive letter or path at that time. 

🌚Use the Format Partition page to determine whether and how the volume should be formatted. If you want to format the volume, choose Format This Volume With The Following Settings, and then configure the following options: 

File System Sets the file system type as FAT, FAT32, or NTFS. NTFS is selected by default in most cases. If you create a file system as FAT or FAT32, you can later convert it to NTFS by using the Convert utility. You can’t, however, convert NTFS partitions to FAT or FAT32. 
Allocation Unit Size Sets the cluster size for the file system. This is the basic unit in which disk space is allocated. The default allocation unit size is based on the size of the volume and, by default, is set dynamically prior to formatting. To override this feature, you can set the allocation unit size to a specific value. If you use many small files, you might want to use a smaller cluster size, such as 512 or 1,024 bytes. With these settings, small files use less disk space. 
Volume Label Sets a text label for the partition. This label is the partition’s volume name and by default is set to New Volume. You can change the volume label at any time by right-clicking the volume in Windows Explorer, choosing Properties, and typing a new value in the Label field provided on the General tab. 
Perform A Quick Format Tells Windows 7 to format without checking the partition for errors. With large partitions, this option can save you a few minutes. However, it’s usually better to check for errors, which enables Disk Management to mark bad sectors on the disk and lock them out. 
Enable File And Folder Compression Turns on compression for the disk. Built-in compression is available only for NTFS. Under NTFS, compression is transparent to users and compressed files can be accessed just like regular files. If you select this option, files and directories on this drive are compressed automatically. 

🌚Click Next, confirm your options, and then click Finish. 

The Windows 7 Disk Management tool will now show the space configured as a new partition.

that's it for the first step 

2)How to Format your Computer:
🌚 prepar your bootable CD or DVD or USB 

🌚 Set your BIOS to boot from CD :  
To do this, restart the computer and enter the setup screen when the manufacturer logo appears. The key to do this will be displayed, and varies by manufacturer. The most common keys are F2, F10, F12, and Del.

• Once in the BIOS menu, select the Boot menu. Change the order of devices so that your computer boots from CD before booting from the hard drive. Save your changes and exit. Your computer will restart.
• If you are installing from a flash drive, then you will need to set the BIOS to boot from removable storage
• 
  

🌚 Begin Setup : 

If the CD has been inserted and the BIOS is set correctly, you will see a message telling you to “Press any key to boot from CD…” Press a key on the keyboard and the setup process for Windows 7 will launch.

• Your system may automatically launch the setup program without asking you to press any key.

🌚 Watch the Windows files load :

 After completion, the Windows 7 logo will appear. No files have been altered on your computer yet. Your data will be deleted in later steps.

🌚 Choose your preferences : 

 You will be prompted to confirm your Language, Time & Currency format, and Keyboard or input method. Select the appropriate options for you and click Next.

🌚 Click Install Now : 

 Do not click Repair Computer, even if you are repairing a computer by reinstalling Windows. Once clicked, Setup will begin loading the files it needs to continue.

🌚 Read and accept the terms : 

In order to advance, you must indicate that you have read and agree to Microsoft’s terms of use. Be sure to read through it so that you know your rights and limitations as a user.

🌚 Choose Custom install : 

 This will allow you to perform a clean installation. Formatting the computer means wiping it of all the data that is on it, so you will be performing a clean installation, so that you will be given the option to erase the disk.

🌚 Delete the partition : 

 A window will open asking where you would like to install Windows. In order to perform a clean install, you need to delete the old partition and start with a clean slate. Click “Drive options (advanced).” This will give you the ability to delete and create partitions.

• Select the partition of your existing operating system and click the Delete button.
• If your hard drive has multiple partitions, be sure to delete the correct one. Any data on a deleted partition is lost for good.
• Confirm the deletion process.

🌚 Select the Unallocated Space and click Next :

 There is no need to create a partition before you install Windows 7, this is done automatically.

🌚 Wait while Windows installs files : 

 The percentage next to Expanding Windows files will steadily increase. This part of the process can take up to 30 minutes.

• Windows will automatically restart your computer when finished.
• Setup will launch again, and a message will tell you that Setup is updating registry settings.
• Setup will then configure your computer’s services. This happens every time you start Windows, but will happen in the background next time.
• A window will open letting you know that Windows is completing the installation. Your computer will restart again when this is complete.
• Setup will now load drivers and check video settings. This part does not require any input from you.
  

🌚 Enter your user name and computer name :

 Your username will be used to log in to the computer and personalize your account. Your computer name is the name that your computer will display on the network.

• You can add more users later through the Windows 7 control panel.
• Windows will ask you for a password. This is optional but highly recommended, especially if the computer will be accessible by users other than yourself. If you’d rather not have a password, leave the fields blank and click Next.

🌚 Enter your product key : 

 This is the 25-character key that came with your copy of Windows. Check the “Automatically activate Windows when I’m online” to have Windows automatically verify your key the next time it is connected to the internet.

🌚 Select your Windows Update option :

To make sure that your copy of Windows runs securely and stably, it is highly recommended that you choose one of the first two options. The first option will install all updates automatically, the second option will prompt you when important updates are available.

🌚 Select your date and time : 

 These should be correct already as they are linked to your BIOS, but you can change them now if they are not. Check the box if your area observes Daylight Savings.

🌚 Select network preferences :

 If your computer is connected to a network, you will be given an option to identify that network. Most users will select Home or Work network. If your computer is being used in a public place, select Public network. Mobile broadband users should always select Public network.

• Windows will now attempt to connect your computer to the network. This process is completely automated.

---

---

All this information are from my personal experience and based on these sites :

https://technet.microsoft.com

http://www.wikihow.com