Short Answer 
You can adjust volume levels on Windows by using the Volume Mixer and dedicated keyboard volume keys. For both Windows and Mac, accessibility settings allow customization of shortcuts for volume control, and applications often provide their own volume controls for fine-tuning audio.
Step 1: Use the Volume Mixer and Keyboard Controls
For Windows users, start by accessing the Volume Mixer. Right-click on the volume icon in your taskbar and choose ‘Open Volume Mixer’ to adjust levels for different applications. Additionally, if your keyboard has dedicated volume keys (usually with a speaker icon), you can use them to quickly increase or decrease the volume directly without the FN key.
Step 2: Adjust Settings in Accessibility and System Preferences
In Windows, navigate to Settings > Ease of Access > Keyboard to find options for configuring shortcuts that allow volume control with alternative keys. Mac users should go to System Preferences > Sound to adjust the master volume slider. Both systems allow customization to optimize your keyboard’s capabilities for easier access to volume controls.
Step 3: Explore Alternative Methods for Volume Control
Utilize mouse control for quick adjustments by hovering over video or audio players to reveal on-screen volume controls. Additionally, many applications, like video editors or music software, come with their own dedicated volume controls. Right-click on specific clips or tracks and select options like ‘audio gain’ to fine-tune the audio levels as needed.