This is the story:
I have (or should I say had?) Windows 7 "home basic" edition, service pack 1 installed (preinstalled from factory). One day I installed two Linux OS: First Debian 8.3 Jessie and later Ubuntu 14 LTD. Windows still worked perfectly. Notoriously, when I installed Debian the bootloader was changed, grub 2 was installed, and when I installed Ubuntu after that, Ubuntu changed it for Grub 2 (but probably another version) with another background color. All OS worked, except Windows was very slow. Instead of trying to maintain it using i.e. CCleaner, I did a back up and prepared to "restore completely" Windows 7 to a disk image stored from 2012 (I did this 2 days ago) using a program that comes with samsung called "Samsung Recovery Solution 126.96.36.199".
The process went fine until a point in wich asked to reboot the computer (and asked to wait up to 10 minutes depending on the machine) but it did not follow properly, and I know it because in this video another guy does it and his process went differently.
In that video, my process is the same from 0:00 to 3:12 , and inmediately after that, also like in the video it asked for permission to reboot the pc, same dialog as the video (is the 3:15 dialog).
But after that, instead of rebooting and booting into Windows 7 initial configuration interface, it went into Grub, my bootloader, with the familiar screen to choose OS. I choose Windows to see if it worked and this message was displayed:
error: no such device: xxxxxxxxxxxxxxxxxxxxxxxxx error: disk `hotdisk//dev/sda,msdos1'
Press any key to continue...
(xxxxxxxxxxxxxx....) is a number with letters, it just a generic code, doesn't make sense to me to write it for you.
That message had the background color of Grub. After that I pressed key and returned to bootloader main menu to choose OS. I tried again and same errors. I can't boot into Windows anymore. I can, without any problem boot to Debian, and from it I see that my Windows partition was effectively restored, so there is probably some boot loading error that can be fixed.
What can I do to boot Windows normally again? What these errors mean? I don't have evidence this error where cause by dual booting my system, but I regard as possible that installing the two Linux distros and changing boot loader confused the "samsung recovery solution". I hope it's fixable.
EDIT: When writing this question I didn't thought, this was important, but before reading what answer worked for me, realize this: Ubuntu actually got corrupted during a update 2 weeks ago, before this problem. I had to uninstall it with "Boot Repair". So grub returned to the Debian version (the grub that come installed with Debian) . With this information my own answer will make more sense.