Thanks for the quick reply... i already tried all the methods listed there... i even deleted and reinstalled plutonium but nothing changed. Im no IT expert but i certainly have a lot of experience with such problems but this one is very weird since the bo2 steam version has no lags at all... its just plutonium.

hey my pc didnt have any problems with running bo2 and plutonium bo2.
now all of the sudden its lagging and i drop to 20 fps (only in plutonium). in bo2 steam version i still have 120 fps... any idea what caused the problem?