What was said before it all depends what games you're going to be playing. You really don't need a system like Alienware; not worth the cost. You'd be almost better off making your own laptop to meet your specs. If you're really into gaming I would suggest making your own desktop; can get more...
Try doing what the person said above. Making sure your drivers are all up to date. Also is it just the mouse that is having problems? Your mouse could just be malfunctioning, might need a new one.
Have you tried restarting your modem and router if you have one? I've came across this problem, and a simple restart can possibly fix the problem. If the suggestions made to you doesn't work, might have to contact your ISP.
I'm actually current enrolled at a community college for IT. It's a good place to get you're foot in the door with any classes you take. You'll get certified in what you go for, then you can always go take tests on your own time to get certified in other things. They also help set you up with...
I recommend MSO 7. Especially if you're using it for schooling and so on. Definitely is what you prefer.. and what you're familiar with. I wouldn't go with MSO 10..