Upgrade hardware one by one

Upgrading hardware seems to be a need since software are very soon outdated if not upgraded. On upgrading software, we will of course need better hardware, so that it can support the software. When we are going to upgrade some hardware, it's better to install new hardware one by one because when something happened, you can remove the hardware you install cause you know directly and clearly what has caused the problem. If you install three or four hardware at a time, when your computer hangs or the screen go black, you will feel confused (this is important for beginner) and wonder which hardware causes the problem. You'll also be wasting your time with removing and trying. But if you upgrade hardware one by one, you'll save time for troubleshooting.