find a good resource killer and kill everything you dont need running in back ground. try uninstalling vid drivers reboot get newest drivers reboot.
could always try a reformat with fresh install with game and see if thats better
install these two mods easy to set up.
SFSMOD v1.1 (or newer) and Nossao_mod
http://www.kegetys.net/misc/
if you cant find the nossao_mod let me know via pm and i will email it to you.
install, first install the SFSMOD v1.1 (or newer) from:
and make sure it is working. Then, extract this archive to
the IL2COD directory (so you get the "nossao" dir under the game
directory). Finally use -mod=nossao commandline parameter to
enable the mod for launcher.exe.
after the two mods above i have no problems at all stuttering is all gone