Go back to black viper and turn on one item at a time that you turned off if it doesn't fix the problem then move to the next one and try it. They do state that turning off some of these items may cause a problem and if so turn it back on.
It really doesn't matter how much space on the internal drive that the songs take up. What does matter is the total space used on the drive vs free (unused) space on the drive. A minimum of 25% should remain free in order for Windows and programs are able to operate without any delay. Defragmenting periodically helps too.
Laptops, due to using shared memory (RAM) for video seem to have the most problems with skipping and other problems. From what I have seen in here too it doesn't seem to matter how much memory or what operating speed. To get one that doesn't used share memory for video you are looking at well over $1000 price tags.