You can go into settings and set it so that it only downloads the files you want whenever you're not on, for example, late at night when you're sleeping.
Or, you can just pause them while you're playing on the computer.
The most effective method for speeding up a comp where possible is just format the hard disk. Also check to see if you have any useless programs. Uninstall them. Run disk cleanup. Check to see what you have in your temp. Generally have a clear up of your hard disk.If your internet is slow, you should scan your computer for viruses and spyware using suitable programs(for example- avast anti virus or spybot). If you still experience the same problem I would advise you to delete the computer after backing it up, and then installing a new copy of Windows. if your problem is with programs running slowly- I can advise you to download this software, which can extremely help- CCleaner
Check all these and perform speed test here scanmyspeed.comit will be fast