Hello.

I've installed running animation replacer, but deleted it after I saw that it increases the speed of movement.

I deleted animation file and esp. But even after that I still have that vanilla or even bigger running speed (I am using FCOM which lowers it).

And now the question:

Do you know how to restore the original modded speed of running, I know it's just a small detail but it's really irritating running so fast.

I wouldn't like to start a new game (I think that running speed has been saved in a gamesave) and lose few hours of gameplay, when time is so precious (school vacations will end soon in my country). Could please someone help me ?

If you use a bashed patch, build a new one. The game setting that controls running speed may have been saved in your current bashed patch. Also, running speed is a multiple of your walking speed, in case you have something that increases your walking speed.

I made a new bashed patch and rebuilded it and it's the same.

Try http://oblivion.nexusmods.com/mods/7484. You can configure it however you want.