Rebuild a computer

Windows

If your computer is slow, it may be time to start a clean new start. Regularly formatting and reinstalling your operating system can run your computer much longer than you think. It eliminates junk files and things that lead to slow performance. If you regularly back up your files, it should only take about an hour.

1. Obtain or create a Windows installation disc or a USB drive. This is the easiest way to format your computer and restart it. The disk must be the same Windows version as the one you installed. For example, if you use Windows 7, you must have a Windows 7 installation disc. You can either use the disc supplied with your computer or create one yourself. You need a blank DVD or a USB stick with at least 4 GB of free space.

• Windows 7: Download the ISO file with your product key from Microsoft . Download the Windows DVD / USB Download Tool to create an installation DVD or an installation USB key with the currently downloaded ISO file.
• Windows 8: Go to the Microsoft Windows 8.1 download page and click the "Create Media" button. Run the tool and follow the instructions to create an installation DVD or an installation USB stick. 

• Windows 10: Go to the Windows 10 Download page and click the "Download Now" button. Follow the instructions in the tool to download the Windows 10 files and create a DVD or USB stick for installation.

2. Make a backup of all the files you want to keep. When you format your computer and re-install Windows, all files on the hard drive are deleted. Make sure you save all important files in a different location, such as on an external hard drive or in the cloud. All your programs must then be reinstalled.

• Read Backup Data for a guide to back up your important files.

3. Boats from the installation DVD or the USB stick. When everything has been saved, you can start formatting and reinstalling. You will boot your computer from the installation DVD or the USB drive instead of from the hard drive. You have to set your computer accordingly. How you do this depends on whether your computer has been shipped with Windows 7 or earlier, or Windows 8 or later (BIOS vs. UEFI).

• Windows 7 or earlier (BIOS): Reboot your computer and then press the button to enter the BIOS. This button is displayed on the screen during power-up before Windows loads. Usually it's the keys F2, F10, F11or Entf. Open the BOOT menu and set your DVD drive or the USB stick as the primary boot media.
• Windows 8 or later (UEFI): Go to the Start menu and right-click on the Power button. Press ⇧ Shiftand then click "Restart". Choose from the "Troubleshooting" menu, then choose "Advanced Options". Click the "UEFI Firmware Settings" button to open the UEFI menu. In the boot section of this menu you can change the boot order, so that your computer starts from the USB stick or the DVD drive.

4. Start with installation. Press any key on your keyboard when prompted to load the Windows Setup program. It may take several minutes for all required files to be loaded.

5. Select the language options. Before you install, you are prompted to choose your language preferences. Click "Install Now" to start the installation after you've made your selection.

6. Enter the product key. If you are installing Windows 8 or later, you will be asked for your Windows product key. If you are installing Windows 7, you will be prompted for the product key after the installation is complete. You can skip this step if you want to enter the product key later.

7. Select the "custom" installation. So you can delete all data on your computer and restart.

8. Select the drive on which Windows is currently installed. It is listed as a "primary" drive and is usually labeled with your Windows version.

9. Click the "Drive Options" button, then click "Delete. " This deletes the partition and all data on it. It is converted to unallocated space.

• You can repeat this for all other partitions you want to delete and add to your main partition. All data on these partitions are also deleted. Click "Extend" to combine blocks with unallocated space to a single partition.
• You can split your partition into multiple partitions, if you want. This can be useful for organizing the files. Select the unallocated space and click "New" to create new partitions. Just make sure that the partition on which you want to install Windows is at least 20 GB in size.

10. Select the partition on which you want to install Windows and click "Next. " This will start the installation of Windows. Copying the files and installing them take about 20 minutes.

11. Create your user account. When copying the files is finished, you are prompted to create your user account. This account has admin rights. You are also prompted to enter a name for the computer. This is the name that identifies your computer on the network.

12. Enter your product key (Windows 7). If you install Windows 7, you will be prompted to enter your product key. You can skip this at the moment, if you want to enter it later.

13. Select your update settings for Windows. Most users should select the "recommended" options to ensure that everything is up-to-date and secure.

14. Enter the date and time. Your computer should automatically select the correct date and time, but you may have to make manual changes.

15. Identify the type of network you are connected to. Choose the type that best suits your environment. This affects your network security and sharing settings.

16. Start using Windows. After selecting the network type, you will be taken to the Windows desktop. If you have not previously entered your product key, you are now prompted.