Hi, I bought a used laptop Dell Precision m4600 with an nvidia quadro 1000m. I have a windows 7 professional 64 bit on it.The problem is that any time I shut the lid and open it when I stop hearing the fans working and then open the lid, it kinda goes to the login screen, and then freezes, and no matter how long it sits like that, it never wakes up. The login screen is just like a regular one, except it never makes it to a point of showing an actual user icon and the bar where you enter the password, just the mouse, which doesn't respond when I'm touching the touchpad. The only thing that I am able to do, is shut it off by pressing the power button or taking out the battery. I have put the settings to "sleep" and even tried to mess with the BIOS a little bit, but that way I was only able to turn off options of "sleeping" and "hibernation." I mean this isn't a super deadly problem, but when using this for school it's so uncomfortable and I can't really take forever to wait for this thing to restart and stuff like that. Please help! Thank you!