Running Too Many Programs

• All programs consume RAM (virtual memory) while they are being used, and certain programs use more RAM than others. If you are using multiple programs at once, you might try and close one or more of them to help conserve RAM.
  
  

Not Enough RAM

• Sometimes it's impossible to simply shut down programs, so you must install additional virtual memory. If you do not know what type of RAM is compatible with your computer, contact your computer's manufacturer. The manufacturer can also give you concise instructions regarding installing additional RAM.
  
  

Viruses

• Viruses are malicious programs designed to slow down or corrupt your computer. They run in the background of normal processes and use memory. You can remove and prevent viruses with antiviral software. You can download some of these--like Avast or Malwarebytes--free from the internet.