Aqui estão as diretrizes recomendadas da Dell para o seu problema. Observe a caixa em amarelo; Parece que a equipe da Dell previu seu problema.
Reinstall Windows 7 using the Dell Operating System Installation Disc.
To run the installation disc, insert the Windows installation disc into the DVD drive. Restart your computer. When the Press any key to boot from the CD or DVD message appears, press any key to continue.
If the disc does not begin to run, press your computer's Power button and watch for the Dell logo to appear. When the logo appears, press the F12 key to load the Boot menu. If this menu does not appear, try restarting your computer again and pressing F12several times when the Dell logo appears. Once the Boot menu opens, select CD/DVD drive (listed also as CD-Rom or CD/DVD/CD-RW) and press Enter.
When Windows 7 Setup appears, confirm that the Language, Time, Currency and Keyboard Method fields display the correct settings.
On the Windows 7 Installation dialog box, click Install Now.
Review the license agreement, and click I accept the license terms.
On the Which type of installation do you want? window, click Custom (advanced).
On the Where do you want to install Windows window, select the largest internal disc as the Primary Partition, then click Next. If the Primary Partition shows 0GB free, select Unallocated Space and click Next.
Your computer will restart.
Personalize and customize your Windows 7 operating system by following the instructions on the following screens.
When your Desktop screen appears, you are ready for the next step.