How can I make these buttons obviously clickable?

Question

I am building an installer in VB.NET in Windows Forms, and am currently adding a final few things such as objects on the About and Preferences pages.

I know the buttons are clickable, but the user may not:

I'm thinking that the user may interpret the buttons as steps in the installation process, and that they go to the Preferences page when they click 'Install'.

The current page is represented by the button being white:

whilst deactivated pages are represented by the button being grey:

How can I make these buttons look obviously clickable whilst being discrete?

I am unable to have 'fade-in, fade-out' effects due to technical restrictions.

Answer 1

Easiest solution would be to add an underline to inactive links/buttons. If you separate tabs with literally one pixel of white space, they will also look more like clickable tabs.

I also noticed that you didn't respect visual hierarchy, and your CTA got lost and the component thus doesn't look whole (which contributes to tabs not looking like tabs).