After you insert the Windows 7 installation disc into your PC, Windows 7 Setup should start automatically and the Install Windows page should appear.
If Setup doesn’t start automatically:
In Windows Vista, click the Start button, click Computer, open the Windows 7 installation disc on your DVD drive, and then double-click setup.exe.
In Windows XP, click Start, click My Computer, open the Windows 7 installation disc on your DVD drive, and then double-click setup.exe.
If Windows 7 installation still won’t start, here are a few things to check that may help fix the problem.
The Windows 7 installation disc is a DVD. If your PC only has a CD drive, you'll need to get an internal or external DVD drive to install Windows 7.
Inspect the Windows 7 installation disc for physical damage, such as scratches or other visible defects. If the disc is defective, get a replacement disc from the place of purchase or from Microsoft. For more information about the options available in your country or region, go to the Shop webpage.
If the disc was purchased at a retailer, verify that the Windows 7 installation disc is genuine. For more information about genuine Windows, go to the Genuine Windows webpage.
In some countries or regions, you can purchase and download Windows 7 online. If you burned an installation disc from a downloaded file, try burning the disc at a slower speed. For more information about the options available in your country or region, go to the Shop webpage.
If autorun is turned off, you can start Windows 7 installation by browsing to the setup.exe file and double-clicking it as noted at the beginning of the topic.
It's possible that your DVD drive requires an updated driver or firmware before you can install Windows 7. To update a driver:
In Windows Vista, see Update a driver for hardware that isn't working properly.
In Windows XP, click Start, click All Programs, and then click Windows Update. Follow the instructions to install any updates.
If driver updates for the DVD drive aren’t offered in Windows Update, go to the DVD drive manufacturer's website to check for updates. For more information, see Update drivers: recommended links.
If you are trying to start, or boot, your computer from the Windows 7 installation disc (instead of starting Windows 7 setup while your existing version of Windows is running) and the Install Windows page doesn't appear, see Windows 7 installation problem: can't boot from installation disc.