First off, hardware is the internal stuff like your CPU, RAM, or Hard-Drive. It can also be external stuff like USB enabled devices like; mouse, keyboard, printers and external hard-drives. The most common hardware problem I've found is not having enough RAM memory to run more than one program. Most memory sticks are cheap, but if you find that you can't add more memory in a later post I'll show how to increase your memory. Another common issue is a hard drive that is almost full. If you can either move files to an external drive or a CD/DVD then that should help, but if you still see problems in a later post I'll show you how to clean up your drive to get the most space out of it. For the more uncommon hardware issues that can cause a computer to freeze up is when a piece of hardware doesn't have the right software for it or it's not compatible with your system. Its best to contact your manufacturer on what products would play well with your system before purchasing it.
Now software is trickier to pin point as to the cause of the freeze because it could be the operating software, a program you purchased/came with the system, or the driver software for the latest hardware you just purchased.. A little background first, when a program is created it has to be tested and cleaned of any bugs that the developer finds during testing. Almost every piece of software released has bugs in it and for the most part they are harmless. But some bugs could be the cause of the freeze when you try to do certain tasks or actions. When the software causes a freeze you would see the above image, do send the report to the developer so they can fix it. Sometimes its the operating system with all the updates that are sent and uploaded without you knowing, I'll show you in another post how to control that so you know what's going on and why it's important to know.