i played FallOut 3 for long time and it was good till i made new windows ... of course i saved all of my save game to continue playing ... but after i made the new windows and put my save game back to My Document folder and run the game ... i found an error while try to play ... the error here in this pic

[IMG]http://i53.tinypic.com/eu0phg.jpg[/IMG]

when i press yes the game makes the Don't Send error message .... and when i start from another save it goes fine but the in game EXP when i kill any one the Exp doesn't rise

please any one help me ... i can't start all over again

It looks like you had a mod installed when you were using that save and you haven't re-installed it.

If you haven't used mods, or the official DLC, I'm stumped.

Fallout Mod Manager has a feature which can show you what content each save relys on.
You can get this on the Fallout Nexus.

If you get a crash trying to load a save which uses a mod which is no longer present, odds are you had some mod which added a custom perk.
The only safe way to uninstall such a mod is to first remove the custom perks before uninstalling the mod.

Find out what is missing and jack it back in, if you can.