As part of the reinstallation I needed to reinstall Gears of War and have not been able to get my save games to work. I still have the original windows vista partition, so I copied the save game over from the Windows Live folder (sorry the exact path escapes me right now) and I also copied over the checkpoints (although this shouldnt matter) but every time I start Gears of War it puts me right back at the very beginning.
After a couple of hours off and on fighting with this, I came across the following solution of sorts, in Gears of War, open the console (usually tilde ~) and type open
(for a list of map names just google, its easy to find).
When the map loads it will be a mess but just quit back to the menu and restart the level and everything will be ok again. So although I wasnt able to get back to exactly where I left off, I was able to get pretty close which was good enough for me.