To install Windows 7 using the Custom option and formatting the hard disk:
To format your hard disk during Windows 7 installation, you'll need to start, or boot, your computer using the Windows 7 installation disc or USB flash drive.
Turn on your computer so that Windows starts normally, insert the Windows 7 installation disc or USB flash drive, and then shut down your computer.
Restart your computer.
Press any key when prompted, and then follow the instructions that appear.
On the Install Windows page, enter your language and other preferences, and then click Next.
If the Install Windows page doesn't appear, and you're not asked to press any key, you might need to change some system settings. To learn...