link tem um passo-a-passo passo instruções sobre como copiar arquivos de instalação do Windows para o disco rígido, tornando-o inicializável e instalar o Windows 7. A partir do site:
How to CLEAN Install Windows 7 directly from Hard drive – NO DVD or USB needed!!
For example, you have a netbook or desktop that you want to install Windows 7 onto, but can’t use DVD or USB for whatever reason (or don't want to, like me). This method will allow you to boot and install Windows directly from the hard drive. This guide involves plugging the hard drive into another working computer, preparing the hard drive, placing it back in the system, and installing Windows as usual.