If iCloud Photos and iCloud Drive aren't working, you might need to update to iCloud for Windows 7.11.*
To check for updates, open Apple Software Update on your PC. You can also get notified when an update is available — just choose Edit > Preferences, and select when you'd like to check for updates.
For the best iCloud experience, also make sure that your device meets the minimum system requirements.
* This is likely if you're using both iCloud for Windows 7.10 or earlier, and iTunes 12.9.4 or later.