2. Take some time to clean up your computer internally.

Disk Cleanup
Free up space on your hard drive by getting rid of temporary files, Internet cache files, recycle bin files and unnecessary program files.

Here are links to instructions for different Windows Operating systems:
Window XP
Window 7 or 8
Window 10

Disk Defragmentation
Defragmentation allows you to optimize (or analyze) your drives so that your computer runs more efficiently. To get started, shut down all applications.

a. Click on the start button and in the search box, type disc defragmenter and then select disk defragmenter in the results list.
b. Select the drive you would like to optimize (general OS (C:) drive). If the option is available, click Analyze Disk (or Analyze depending on Windows version).
c. Once the analysis is complete and percentage of fragmentation will appear. If this number is above 10%, click on Optimize (or Defragment Disk or Defragment might be shown depending on your version of Windows).
d. Be patient. This could take several minutes to a few hours to finish.

Remove the Dust
Your PC has a fan in it to keep it from overheating. Over time, dust gets sucked into the fan causing it to overheat and slow down performance. You can reduce this by using a low setting vacuum (dust buster or similar hand-held vacuum) to remove the dust from the outside of the fan area. You can also use it to remove dust on the inside but make sure to disconnect your computer from the electricity source and wait at least 30 minutes before using a low setting vacuum. IMPORTANT: be careful cleaning near the cables to avoid disconnecting anything.

Clean-Up Tip #3