This is nothing new, C&C has some lag during cut scenes, it has little to do with your system. As was mentioned, update and mantain your system. As to the question of defragging posed above, 20 hours seems about 19 hours to long for that function, your system will create a temporary file and copy moved files from there, you have to make sure there is some free space on the hard drive, if there isn't you can slow down the function to a crawl.