If your custom icons revert to a generic blank page icon when you restart your computer, it means RocketDock cannot find the file path. This happens if you load icons directly from your "Downloads" or "Desktop" folder and later move or delete that folder. Always place your icon packs inside the C:\Program Files (x86)\RocketDock\Icons directory before applying them. Conclusion

: PNG (recommended for transparency), ICO, and BMP.

What or desktop theme you are currently using?

Standard Windows desktop shortcuts come from various developers, resulting in a messy mix of art styles, resolutions, and colors. A dedicated icon pack ensures every application shares a cohesive design language.