I had this problem with a Toshiba computer that belonged to a friend. I called Toshiba support and they sent me a link to a download. I burned the download to a disc. Then reloaded the computer from the disc.It was the original OS "Windows 7". Worked fine after that. I advised the friend to NOT "free upgrade " the operating system.
A problem was encountered with the first link they sent me, as it was the wrong software. Finally they figured out the mistake and sent me the correct link. The support team I talked on the phone to, was definitely overseas somewhere in Asia.
The link software took overnight to download, I went to sleep and it was still downloading in the morning. I advised friend from now on try to stick with Dell products. The Dell products usually will let you install a Dell "restore disc" provided the Dell computer was originally loaded with that version of Windows.

I hope this helps some.