I recently upgraded to windows 10 on my Dell Inspiron 5720 and I have been getting a lot of lag. When I start up, everything works just fine. However, if I put the computer to sleep or if the screen even turns off when idle, my computer slows down to a crawl. Programs won't open. I have to wait several minutes for the start menu to open and it takes about 10 minutes to restart. Once I restart everything works fine. I am guessing it is a graphics issue, but I don't know how to fix it. Has anyone else had this problem and, if so, were they able to fix it? Thanks!