How to fix corrupted save.
We all know how it feels to lose 50+ hours character because of ♥♥♥♥ing GFWL or whatever.
I found a solution for this problem:
With LUCK you may save 1 character or 2 from the corrupted save file.
1: go to /Documents/NBGI/Dark Souls/(your gamertag)
2: you will see DRAK0005.sl2 file which is your corrupted save.
3: cut or copy the file to desktop or whatever. (back it up)
4: once you have a copy of your save,delete DRAK0005.sl2 from your gamertag folder.
5: launch the game and GFWL will create a fresh save.
6: start a new game and create a random character example: your old corrupted save had 2 characters in it so you must make 2 new ones.
7: after the cutscene just exit to menu.
8: now once in menu select LOAD GAME and replace the new DRAK0005.sl2 with the corrupted one.
9: select the fresh created character from load menu and magic!
with a bit of luck the save will load and your old character will replace the slot.
10: repeat for each slot.
If the game crash on loading a character you are out of luck.
with this method I saved 1 character from corrupted save file.
hope it works peace.