DON'T GET MAD, GET PCBRAD!
Upgrading RAM is an excellent way to improve performance and fix issues related to more demanding software requirements. Are they running Windows 10 with only 4Gb of RAM memory? Photoshop with 2Gb of RAM? This is not enough memory for modern systems. Ensure the customer has enough memory and if they don’t, explain to them what a difference in performance, usability, time savings and overall computing satisfaction it can make for such a low cost. A good way to explain the benefits of a memory upgrade is: “a memory upgrade can make your computer feel 3 years newer."
If you use your computer every day, a daily backup of the files you use most often or modified that day is a good idea. To be sure you've backed up every file, use backup software. ... In case your computer's hard drive fails, make sure you have a copy of your operating system on a CD for reinstallation.
Computers are like cars, they need to be tuned up and cleaned at least once or year or twice per year