I have a HP pc with Windows 7 and a 6 year old Dell monitor attached. Initially there were no problems, but eventually the monitor wouldn't wake up from sleep mode. Now, the monitor will come on for a second and then won't wake up. The desktop is visible for a second before it goes to sleep. The problem has gotten progressively worse over the past 2 months. Two months ago it would come on and stay on, now it only comes on for a second. Is it a video card issue? Also, a sidenote, even though I put in a valid product code, it says it isn't a valid copy.