Tengo una computadora con Windows 7. Cuando lo inicio, obtengo la animación de inicio habitual, el LED del disco duro parpadea pero luego la pantalla se pone negra y no pasa nada más. No hay sonido, por lo que no hay actividad, no hay cambios cuando presiono cualquier tecla o los botones del mouse.

Cuando inicio la computadora con un sistema en vivo Fedora 23 Linux desde USB pendrive, no tiene problemas, todo funciona de inmediato.

Cuando inicio la restauración del sistema de Windows (he probado varios puntos de restauración), tarda unos minutos con la actividad del LED del disco duro, pero luego aparece un error: 0x8000ffff, y algo de texto, que es un error no especificado. No es útil.

Estoy no muy experimentado con sistemas recientes de Windows, pero muy experimentado con Linux y Mac OS X. Así que necesito ayuda aquí.

Ahora la pregunta es: ¿Cuál es la mejor y más rápida forma de hacer que la computadora vuelva a funcionar con el antiguo sistema Windows 7? Cuando uso el CD de instalación de Windows 7, ¿hay alguna forma de instalarlo en el sistema anterior? ¿Esto podría funcionar? ¿Funcionará el software instalado (o al menos la mayor parte)? No lo he probado, ya que no quiero destruir nada, hasta que sepa cuál es el mejor enfoque.

La respuesta más completa a mi pregunta de novato parece ser esta, que desafortunadamente me dice que debo iniciar mi sistema Windows 7 ( "debo iniciar sesión en Windows 7 en una cuenta de administrador para poder realizar una instalación de reparación" ) Lamentablemente, esto no es posible en mi caso.

http://www.sevenforums.com/tutorials/3413-repair-install.html

Citado de la fuente.

Realice una instalación de reparación si:

A System Restore did not help fix your Windows 7.
There is no other easier option left that can fix your Windows 7.
You DO NOT want to do a Clean reinstall of Windows 7.
You DO want to preserve your user accounts, data, programs, and system drivers.

ARTÍCULOS QUE SERÁN RESTABLECIDOS POR DEFECTO O AFECTADOS:

Sounds
Services
Visual Effects Settings
Device Drivers - Be sure to have these handy to reinstall. They do not always remain after the repair (upgrade) install.
You may lose the ability to sign on to MSN Messenger, to solve this problem have a look at this thread Unable to sign in to WLM.
You may lose your custom themes due to not having permisions set on the old themes. Go to the hidden themes folder at C:/Users/(User-Name)/AppData/Local/Microsoft/Windows/Themes, then Take Ownership of the themes folder and you will now have all your themes back.
It has been reported that you may also lose your Media Center gadget after doing the repair install.
Windows Updates will need to be checked and reinstalled again.

Advertencias

You can only do a repair install with the same edition Windows 7 installation disc for the same edition of Windows 7 that you have installed.
You cannot use a OEM Windows 7 "Factory" Restore/Recovery type of installation disc that came with or created from a store bought computer to do a repair install with. These can only be used do a clean install instead.
You can do a repair install on a factory OEM installation with the latest official Windows 7 with SP1 ISO file here: Microsoft: Windows 7 Direct Download Links, and use Windows 7 USB-DVD Download Tool to create a bootable DVD or USB flash drive with the ISO to do the repair install from within Windows 7.
You can use a retail OEM Windows 7 installation disc to do a repair install with.
You can use a retail (full or upgrade) Windows 7 installation disc to do a repair install with.
You cannot do a repair install with a System Repair Disc. A System Repair Disc is not a installation disc, and will only boot to the System Recovery Options screen.
If you have a 32-bit (x86) Windows 7 currently installed, then you must use a 32-bit Windows 7 installation disc to be able to do a repair install with.
If you have a 64-bit (x64) Windows 7 currently installed, then you must use a 64-bit Windows 7 installation disc to be able to do a repair install with.
You can use a retail Windows 7 SP1 installation disc (ex: Technet (available), MSDN (available), or retail (when available)) to do a repair install with on a currently installed Windows 7 SP1.
You can use a Windows 7 SP1 installation disc (ex: Technet (available), MSDN (available), or retail (when available)) to do a repair install with on a currently installed slipstream Windows 7 SP1.
You cannot use a slipstream Windows 7 installation disc to do a repair install with on a currently installed Windows 7 SP1.
You cannot use a slipstream Windows 7 installation disc to do a repair install with on a currently installed slipstream Windows 7 SP1.
You can only do a repair install from within Windows 7.
You cannot do a repair install at boot or in Safe Mode.
You must be logged into Windows 7 in a administrator account to be able to do a repair install.
You must have at least 8.87 GB + what is currently being used of free space (more if you have a larger installation) on the hard drive/partition Windows 7 is installed on to do a repair install.
If you changed the default location of a user account's profile folder, then you will need to change it back to the default C:\Users location first.
If you moved the default location of a user folder, then you will need to change it back to the default C:\Users\(user-name) location first.

Actualizar

Finalmente lo hice, lo que se recomendó en esta respuesta + recuperé mis archivos del Windows.olddirectorio. Tuve que instalar todo el software nuevamente. Pero al menos pude recuperar las configuraciones de la %APPDATA%carpeta.