Post completing installation this issue is common.
You need to follow below steps:
1. Go to app/etc folder
2. edit di.xml file
3. search for word "symlink" and replace it with "Copy"
4. Save the changes and close the file.
5. Navigate to pub/static folder now and Delete all files and folders other than “.htaccess”
6. Go back to admin screen and refresh to see the image changes.
7. All the options will be enabled now.
This worked for me for 4 different environments i installed M2. Hope this helps
