When you notice your computer is slower than you’d like, then it helps to ask “How is it slow?” There are three main ways a computer can act slowly and each one comes from a different set of possible sources.
The first kind of slowness is slowness getting started. If your computer takes a very long time to start or reboot, but once it finishes booting it works normally, this is slowness getting started. It is typical of older computers with slower or dying hard disk drives. But it may also be due to a lot of software loading at boot time, such as complex security systems, Adobe down-loaders, backup utilities, Spotify, and so forth. In bad cases, you may find that it takes a long time to open a program or document but then the computers works normally until it is time to save the document.
The second kind of slowness is slowness on the Internet. If your computer acts normally when working in Word or other local software, but web pages take a long time to load, this is slowness on the Internet. It is typical of computers connected to slow Internet connections. But it may appear with certain types of malware infestations. Ensure you have a top-tier professional-grade anti-virus product, such as Symantec (Norton), ESET, Kaspersky or Trend Micro.
The last kind of slowness is general slowness. If your computer is slow at everything and particularly slow when there are many programs open or many tabs open in your web browser, this is general slowness. It it typical of older computers with low RAM, although some types of malware infestations could eat into the RAM in ways that get hidden from the system performance monitoring tools. But this sort of slowness may also appear where the motherboard and other components are starting to degrade.
Those are the three ways a computer can act slowly. Hopefully this will help you think about your computer performance and how to improve it. If you suspect malware, try a scan with Malwarebytes Anti-malware. If that finds nothing, then consult with your local computer technician, and be sure to specify how and when you notice the slowness plaguing you.