audio player and performance issue

Sir, 

I have XPS L502x laptop. My service tag is 50x2vq1. I have facing some issues-

1. Audio player is stacking during songs play. It is automatically pause for few seconds and then start.

2. Games are lagging too much.

3 Working slow. 

4 Heating issues are there.

plz proved best solution for it

Regards

Rishi Shukla