I upgraded to windows 10 and all was great. I had no issues upgrading. But I did notice that the sound has become muffled and not the same as windows 8.1. the internal speakers work fine, but when I plug in a pair of headphones is when it becomes muffled. If I open up the playback devices, it never shows my headphones in the options. I have also troubleshooted the sound problems and it cant find anything. Someone please help, I cannot enjoy any music or movies now.