Lag Black Ops. Please help. (Call of Duty: Black Ops)

The game lag.Here is a direct hard lag.To this set of persons. a Year ago and was normal.Downloaded now and lag.(very much).Replaced 4 Repack all the same.The comp is the same.Put the box on a minimal salary and no-th-th.Lag is equivalent to the maximum speed.Well, maybe 1 fps increased.Oh Yes emboss maximum 17 fps.Help would be grateful,but don't write like buy litsuhu,change the Repack,go to config and change the 1 to a 0 and you certainly don't want to write about upgrading.Just what helped you.