Like anything you use on a daily basis, after normal wear-and-tear over years, a product might just no longer work anymore (similar to cars, televisions, and other household items). In the case of computers, I typically recommend to friends and family to run through a few steps to determine if they really do need to say goodbye to an old system:
- Do you clean up old software and remove unnecessary data?
- Do you run updates on the system (firmware, operating system, and software updates)?
- Have you run antivirus or anti-malware scans?
- Could you spend a little money on extra hardware to speed things up? Have you ever run hardware diagnostics?
Typically, the first 3 questions can be easily taken care of and diagnose if there are issues on the software side. Sometimes I recommend a fresh operating system install (after backing up your data and noting what software you use) just to get things running nicely again. If that doesn’t do the trick, it’s a good thing that hardware providers tend to have hardware diagnostic software that you can run (Ex: Dell Diagnostics, HP PC Hardware Diagnostics, Apple Diagnostics, etc). Usually you download the software onto a bootable USB drive and boot into the diagnostics software itself. With newer systems, they tend to ship with a factory diagnostics partition already installed on the drive, which you can boot into as well.
Usually, I recommend new hard drives or addition of RAM for most slow systems after double-checking if hardware diagnostics found anything wrong with the system (it will specify whether your system has faulty RAM, CPU, video card, or numerous other pieces of hardware). In the case that the system has good hardware and recently cleaned up software, yet it still seems bogged down, it might just be that you do need a new system at this time.