Updated today (3/4) and now I can't boot.

[Şerban S.]

UPDATE -   :55:

[...] now I am able to get Windows to boot up!  VERY HAPPY - at least I can work now.  When I set the Linux HD to position #1 in boot up that is when I have the problem.  [...] Tell me what you think...

Hello!
My best guess, due to this behaviour and the fact that you have distinct PHYSICAL partitions/drives for booting each system, is that something went wrong during the GRUB installation process.
Many people treat lightly one important step of the setup process: the GRUB installation device.
Since you switched the primary boot device from Linux to Windows, I suspect you installed GRUB on the /dev/sda/ partition, which in fact is the default option.
This is where I suspect the mess showed up, for some reason. It is well known that Windows is in such a great love affair with Linux, that it will gladly see it dead. It is impossible to know exactly why Windows crushes GRUB so, instead of installing GRUB on the same partition where Windows resides, I chose a different path:
(A) Setup Windows, on /dev/sdaX and leave the Windows installer and bootloader do their jobs;
(B) Setup Linux Lite on /dev/sdbX AND the GRUB bootloader, on the same device, here, being /dev/sdb
.
The only shortcomming of this solution, is that you need to press F12 each time you boot, in order to choose the drive you want to boot (since both are bootable).
IMHO, this is by far a better solution than struggling with countless installations, that for some unknown reason, fail at some point.
Further more, if you setup from firmware Windows as primary boot device (say... /dev/sda/), you only need to press F12 IF you want to boot Linux, since Windows, as I understood, is your main (primary) OS.
As for the backup, my policy is very simple: backup whatever. Who knows when the day comes and I (you) need it?!
Hope this solves the problem!
Good luck!
Best regards!