vipingo :
Is there any way to do that without losing my files,apps and downloads?
with a reinstallation of the os there's no real way to keep your apps, unless they're stand alone (I'll get into this)
The only real way to keep everything is to take your drive with everything on it, put it into another rig, and transfer what you want to keep onto another drive. Transfer everything that you want to keep onto the other drive. Apps are tricky though because they may not work when transferred back to your computer after the os is reinstalled. That and the fact that you may not have saved every file that the app needs to work.
There's no real way to save everything, and reinstall the os without transferring your data to another drive. When you install windows it wipes the drive you're installing windows on to make a fresh partition.
ps. If you do decide to transfer your data make sure that you boot from the main drive on the other computer, and NOT the drive from your black screen computer. You most likely will not even make it to windows if you boot from the drive that's coming out of the black screen computer.