3d Screen lag after deleting

Hello everybody,

Lately I have been having a bug and it is showing some kind of 3d screen. I used the link (http://forums.na.leagueoflegends.com/board/showthread.php?t=3957007) to get rid of the bug, but after I uninstalled the 3d drives, I am lagging the whole time ingame. It looks like my computer can not handle the game anymore. Does somebody know a solution to this?

Kind regards,

YNico