Steps to change desktop icon in Windows 10:
Step 1: Press Windows+I to open Settings panel, and click Personalization to access Personalization settings.
Step 2: Tap Change desktop icons on the top left in the Personalization window.
Step 3: In the Desktop Icon Settings window, select the icon of This PC and click Change Icon.
Step 4: Choose a new icon from the list, and tap OK.
Tip: You can incidentally change the icons of Network, User’s Files and Recycle Bin by repeating the third step and the fourth step.
Step 5: Click OK to confirm the change.
As the following screen shot shows, the icon of This PC has been changed.