Upgrade Dell XPS 15 L502X to Windows 10

Yesterday I upgraded my Dell XPS 15 L502X from Windows 7 to Windows 10. The whole process was smooth except a few problems.
Before upgrade, I uninstalled some software I rarely or seldom used.

• The Dell Stage should be uninstalled; it is not compatible with Windows 10.
• OneDrive should be uninstalled too.
• Firewall software should be uninstalled unless it is compatible with Windows 10.

After upgrade, there were a few issues:

• No sound: download the latest driver from Dell and reinstall.
• No HDMI audio:download the latest driver from NVIDIA  and install.
• OneDrive not working: probably you have OneDrive installed before upgrade and haven’t uninstalled it before upgrade. In Windows 10, search OneDrive, uninstall the OneDrive (Desktop app), and unlink the account via OneDrive tray icon.
• Could not access Internet: the Windows firewall is set to block everything. Change to the default value “Allow” or disable it for now.