I have multiple in-game Louis Letrush

Solution 1:

From http://uesp.net/wiki/Skyrim_talk:Louis_Letrush#Louis_Letrush_Clone_Glitch :

Louis Letrush Clone Glitch

The glitch produces multiple copies of Louis Letrush. The cause is currently unknown. This primarily occurs outside of Whiterun Stables.

Semi-Confirmed Details

• Glitch seems to depend on the completion of Letrush's related quest 'Promises to Keep'.
• Initial glitch cause is unknown.
• However further copies of Letrush cloned upon the use of carriages.
• It appears impossible to kill Letrush (and any of his clones), perhaps due to his essential status.

(I am assuming you have the PC version, since you mentioned replacing your graphics card and you've posted a PC screenshot.)

Install the Unofficial Skyrim Patch (Bethesda forums thread) to fix it (and prevent more Louis Letrush clones from spawning). One of its fixes is:

Louis Letrush should no longer duplicate at the Whiterun Stables fast-travel marker or attack the player for no apparent reason.

If it doesn't fix it or you'd rather not install it, you could also 'remove' Louis Letrush from the game, but it's better to do this after you've already finished the quest related to Louis Letrush (Promises to Keep), to avoid bugs related to that quest.

Make a save game first, and then in the game, open up the console by pressing ~, then click on one of Letrush's clones (RefIDs of the clones start with 'FF', original does not start with 'FF'), type disable and then markfordelete. This will 'remove' the Louis clones from the game. I'd do this for each clone, and then try to keep the original Louis. You may disable and markfordelete the original Louis if you want to, too.

Solution 2:

From this source, it says: "Upon entering the city at whiterun stables, after completing the quest 'Promises To Keep', upto 3 or 4 Louis Letrush's can spawn there" As far as I no there is no solution but I dont think this is too major of a bug so you should be fine