Back Up Data
Data is the most important thing to protect in your PC. It is crucial for you to back up your data especially if you have been using your PCfor years. You might not know exactly when your PC will break down or be infected with virus or ransomware.
The simplest way to back up your data is to import your data/files to a pendrive or external hard disk. You can retrieve back your data if suddenly your PC malfunction.

Clean Dust From Your PC
Computers easily collect dusts, a dusty PC will trap heat which leads to reduce in performance and lifespan.
To clean your PC, open up the case and blow out the dust especially dust that clogs your PC fan. Cleaning once a year is good enough.

Tidy Your Cables
Clean and neat cables will prevent you from stress when figuring out which computer ports it belongs to. If you have lots of peripherals, consider using cable management to tidy up. Not only it is easy to figure out which cable belongs to which peripherals, it also looks tidy. You can just use simple cable wrap to neaten it up.

Run Antivirus Scan
Any computer that is connected to the internet must have an antivirus software. There are variety of antivirus in the market, just choose and install which is suitable to your liking. Antivirus will monitor and remove threats from your PC. Do a full scan run at least once a month. You can also set a schedule scan if you are too busy or forgetful.

Uninstall Application
Facing with slowing down PC? Maybe you have a bunch of applications / software installed which you don’t even use. Why not take the time to uninstall any unused programs.
To properly uninstall a program, go to Control Panel -> Uninstall a program -> choose a program you want to uninstall -> double click it to uninstall

Run Ccleaner and Defragmentation
Besides unused application, web browsing temporary internet files and cookies take up disk space. These files will slow down browsing speed. Ccleaner get rids of these files in click. It also can get rid of things in Recycle Bin and Thumbnail cache.
Once you clean up with Ccleaner, time to run Defragementer. This will help organize your files, leading to faster disk access time and improved system performance. To start Degragment, go to Start -> All Programs -> Accessories -> System Tools -> Disk Defragmenter