To install Windows by performing a custom installation

When you choose Custom, you install a new copy of Windows on the partition you select. This erases your programs and settings.

Back up any files and settings you want to keep so that you can restore them after the installation. You must manually reinstall your programs when the installation is done. For information about how to restore your files after a clean installation, go to How to restore your personal files after you perform a custom installation online.

1. Turn on your computer, insert the Windows installation disc into the computer's DVD or CD drive, and then do one of the following:
   • If your computer already has an operating system installed and you want to replace it with Windows 7, and you don't want to change any partitions, go to step 2.
   • If your computer doesn't have an operating system installed or if you want to create, extend, delete, or format partitions, you need to restart your computer with the installation disc inserted in your CD or DVD drive. This causes your computer to start (or "boot") from the installation CD or DVD. If you are asked to press a key to boot from DVD or CD, press any key. If the Install Windows page appears, go to step 2.
     If the Install Windows page doesn't appear and you're not asked to press a key to start from DVD or CD, you might have to specify that your computer use its DVD or CD drive as the startup device. To do this, you need to change settings in the computer's basic input/output system (BIOS). To learn how to do this, see Start Windows from a CD or DVD. After you select your DVD or CD drive as the startup device, restart your computer, and then start Windows from the installation DVD or CD as previously described.
2. On the Install Windows page, follow any instructions that are displayed, and then click Install now.
3. On the Get important updates for installation page, we recommend getting the latest updates to help ensure a successful installation and to help protect your computer against security threats. You need an Internet connection to get installation updates.
4. On the Please read the license terms page, if you accept the license terms, click I accept the license terms.
5. On the Which type of installation do you want? page, click Custom.
6. On the Where do you want to install Windows? page, do one of the following:
   • If you don't want to specify a specific partition to install Windows on, or create partitions on your hard disk, click Next to begin the installation.
   • If you already have another existing partition with enough free space and want to have more than one operating system on the same computer, you can install Windows on that partition. This is called a dual-boot or multiboot configuration. (If you do this, be sure to install Windows on a different partition from the partition where your current version of Windows is installed.) Select the partition you want to use, and then click Next to begin the installation.
   • If you want to create, extend, delete, or format a partition, click Drive options (advanced), click the option you want, and then follow the instructions. Click Next to begin the installation. (If the Drive options (advanced) option is disabled, you need to start your computer using the installation disc.)
7. Follow the instructions.

   Note

   • If you delete or format a partition that contains a version of Windows, all data on the partition is permanently deleted. However, if there is an existing copy of Windows on the partition you selected, but you do not format or delete the partition, user files are saved to a Windows.old folder on the partition, which you can browse to after the installation completes. However, you should still back up your user files before performing a custom installation. For example, if you have encrypted files, you might not be able to access them after installing Windows. If you’ve backed up your user files and then restored them after installing Windows, you can delete the Windows.old folder.