DDJ 400 Lagging

Super frustrated with audio issues and lagging when I play a track. I've researched all over the place and it seems this is not an unusual issue. I've done all the fixes that have been recommended. My computer is new (Dell Inspiron 5000 64bit) and everything was working fine until about a week ago. Every time that I try and play a track, it's choppy and lagging even with adjusting the buffer and I've set the buffer quite high. Help! I've been streaming twice a week and now can't even stream as it sounds so terrible.