The most commons reasons for a computer to run slow are listed here.  If you need help getting your computer running fast again then contact a Computer PRO.

It’s Busy

Your computer has a finite amount of RAM and processing power.  When applications over utilize the RAM or CPU your computer will begin to run slow as it tries to catch up on the backlog.  The most common thing that causes this is having too many items open (RAM) or having processes that are heavily using the CPU.  The best way to isolate this type of issue is by doing the following:

1. Windows – Use the Ctrl+Alt+Del keyboard commands to open Task Manager.  You’ll want to initially look at the ‘Performance’ tab to see if anything if the CPU or RAM is spiked continually.  If either one is you’ll want to go to the ‘Processes’ or ‘Details’ tab and sort by CPU or RAM so you can see which things are the biggest offender.  Once you’ve identifed what is over utilizing your resources you can close it, remove it from startup or uninstall it.Another thing to check in windows is if your power settings are set to ‘High Performance’.  Some computer models, especially laptops, are configured to run a little slower to conserve battery.  You can correct this by going to Control Panel>Power Settings>and select ‘High Performance’.
2. Mac – Go to Finder and search for ‘Activity Monitor’.  Once ‘Activity Monitor’ is open you’ll want to review any processes or programs that are using a lot of CPU or RAM

It’s Hot.

Heat is slightly more difficult to diagnose.  This issue is especially common in laptops.  The fans inside of a computer are not set to run all the time but they should run as the computer heats up.  If they don’t or if there is an external factor (like the laptop being set on a bed where all of the exhaust ports are covered by the blankets), the computer will overheat and run slow.  In some more extreme cases the computer will turn off or reboot to save itself from completely over heating.

It’s a Hardware problem. 

The most common piece of hardware that causes a computer to run slow is the hard drive.  Hard drives are only designed to perform reliably for a set of hours suggested by the manufacturer.  After those hours are exceeded the hard drive is more prone to failure and, in most cases, will begin to run more slowly.  Additional factors that can cause hard drive failures are manufacturer defects or abuse (i.e. dropping the computer).  These types of things can quickly decrease the life of the hard drive.  The best way to try to diagnose a potentially failing hard drive is to use tools like ‘HDD Health’ or ‘Passmark Disk Performance Test’ and also to review the Windows System event logs for disk errors.

It’s Old.

Most computers are designed to be relevant for around 3-4 years.  After that time the hardware is more prone to failure (see #3) and the software applications have typically outgrown the capacity of the hardware (see #1).  This doesn’t necessarily mean you need to get a new computer every 3-4 years.  I’ve worked with people that have had computers for 10 years or more!  But it does mean that you may need to be a little more patient while the older computer tries to run the latest applications.