If your computer's performance has dropped, we recommend that you reinstall the operating system. In this case, the computer will work without interruptions for a long time. Reinstalling your system will remove unnecessary files and settings that slow down your computer's performance. If you regularly back up the files you need, the whole process will take about an hour.
Steps
Method 1 of 2: Windows
Step 1. Create a Windows installation disc or USB flash drive
You will need it to reinstall the system. The system version on the disk / drive must be the same as on the computer. For example, if your computer is running Windows 7, create a Windows 7 installation disc. You can use the disc that came with your computer, or you can create one yourself. To do this, you need a blank DVD or flash drive with at least 4 GB:
- Windows 7: Use your product key to download a disc image (ISO file) from Microsoft. Then download the Windows DVD / USB Download Tool to create an installation disc or flash drive.
- Windows 8: Go to the Windows 8.1 download page and click Create Media. Run the utility and follow the instructions on the screen to download the files you want and create an installation disc / drive.
- Windows 10: Go to the Windows 10 download page and click Download Tool Now. Follow the instructions on the screen to download the files you want and create an installation disc / drive.
Step 2. Create a backup copy of the files you need
When you reinstall the system, all files on the disk will be deleted. Therefore, copy your important files to an external hard drive or cloud storage. When the system is reinstalled, the required programs must be reinstalled.
To learn how to back up important files, read this article
Step 3. Boot from the installation disc or flash drive
Once you've backed up your important data, you're ready to reinstall your system. To do this, boot your computer from a DVD or flash drive, not from your hard drive. But first, you will have to configure it to boot from the installation disc / drive. This process is system dependent (Windows 7 and earlier or Windows 8 and later), meaning you need to enter BIOS or UEFI.
- In Windows 7 and earlier, you need to restart your computer and then press the key several times to enter the BIOS. It will be displayed on the screen (under the logo of the manufacturer of the computer or motherboard) when the computer boots up. Typically, you need to press the F2, F10, F11, or Del key. Open the BOOT menu and select DVD or USB drive as the primary boot device.
- In Windows 8 and later, open the Start menu and right-click on Power. Hold ⇧ Shift and click Restart. From the menu that opens, choose Troubleshoot> Advanced Options. Click UEFI Settings to open the UEFI menu. In the BOOT section, select the DVD drive or USB drive as the primary boot device.
Step 4. Start the installation process
When prompted, press any key. It may take several minutes to download the installation files.
Step 5. Select a language
Before starting the installation process, you will be prompted to select a language. Select your language and then click Install Now to start the installation.
Step 6. Enter your product key
Do this if you are installing Windows 8 or later. If you are installing Windows 7, you will need to enter your product key when the installation is complete. Skip this step if you want to enter your product key later.
Step 7. Select the "Custom" option
This will allow you to delete all data on the disk and reinstall the system.
Step 8. Select the drive where Windows is installed
It will be marked as "Primary"; also, the Windows version will be displayed opposite it.
Step 9. Click on "Disk Options"> "Delete"
This will delete the partition and all data. The section will display "Unallocated space".
- Repeat the described steps with other sections if you want to delete them and combine them into one. Remember that all data on these sections will be deleted. Click "Expand" to merge the deleted partitions into one.
- Divide the section into multiple sections if you like. This is useful for organizing files. Select the unallocated space and click New to create new partitions from the unallocated space. Make sure that the partition on which you are going to install Windows is at least 20 GB.
Step 10. Select the partition where Windows will be installed and click "Next"
The Windows installation process will begin and will take about 20 minutes.
Step 11. Create a user account
When the files are copied, you will be prompted to create a user account. This account will have administrator rights. You will also be prompted to enter a computer name. This is the name under which the computer will appear on the network.
Step 12. Enter your product key (Windows 7)
If you are installing Windows 7, you will be prompted for your product key. Skip this step if you want to enter the key later.
Step 13. Configure Windows Update
Most users can choose the "Featured" option.
Step 14. Set date and time
The computer should automatically adjust the date and time; otherwise, set them manually.
Step 15. Specify the type of network to which you are going to connect
Select the type of network that best suits your equipment. This will affect your security and network sharing settings.
Step 16. Get started with Windows
When you choose your network type, you will be taken to the Windows desktop. If you have not entered your product key yet, you will be prompted to do so.
Method 2 of 2: Mac OS X
Step 1. Back up the files you need
When you reinstall the system, all files on the disk will be deleted. Therefore, copy important files (documents, photos, videos, etc.) to an external hard drive or cloud storage. To learn how to back up important files, read this article.
Step 2. Restart your computer and then press and hold ⌘ Command + R when you hear a beep
Release the keys when the Apple logo appears on the screen.
Step 3. Select the wireless network you want to connect to
You may be prompted to select a wireless network. If not, connect to the internet with an Ethernet cable. To reinstall OS X, you need an active internet connection.
Alternatively, you can click on the wireless network icon in the upper right corner and select the desired network
Step 4. From the "Recovery" menu select "Disk Utility"
A new window will open displaying all the drives connected to the computer.
Step 5. Select your hard drive and click "Erase"
The displayed parameters can be left unchanged; enter a new disk name if desired. Click "Erase" to confirm your actions. Close Disk Utility when the erasing process is complete to return to the Recovery menu.
Step 6. Select "Reinstall OS X" and click "Continue"
The OS X installer starts. A message appears stating that your computer will be verified by Apple.
Step 7. Read and accept the license agreement
Do this to proceed with the installation of the system.
Step 8. Select the drive where you want to install OS X
Select the disk that you just erased with Disk Utility.
Step 9. Enter your Apple ID
You will be prompted for your Apple ID to verify that you have a license for the operating system.
Step 10. Wait for the files to download
The installer will begin downloading the files that are required to install OS X. The time it takes depends on your internet connection speed.
Step 11. Select your country and language
They should be selected by default.
Step 12. Connect to the network
Select a wireless network and enter the password for it. If you are connected to a network using an Ethernet cable, you do not need to select a network.
Step 13. Select the method of information transfer
You can restore a Time Machine backup or transfer files from a Windows computer. After choosing one of these methods, follow the instructions on the screen to transfer files. To set up your computer as new, select the "Do not transfer information" option.
Step 14. Sign in with your Apple ID
This will give you access to the store and your iTunes purchases.
Step 15. Create an account
By default, the system will use your Apple ID as your computer account. Instead, you can create a new account.
Step 16. Complete the installation process
Set a number of advanced options before you go to the desktop.