I know this subject has been brought up before a few times and the Directory Opus team has responded emphatically that they do not plan to change the application's icon that represents the sun and a disk.
But, I want to plead with Directory Opus developers to seriously consider designing a much better icon. An icon's main purpose is to indicate what that icon is supposed to do. Eventually, even if the icon is only slightly related to what it does, people's brains eventually associate the two.
I have been using it for slightly more than a month and my brain still doesn't associate what the Directory Opus icon stands for when it appears on the taskbar. Usually, it only takes about a month for the brain to form neural links that associate two objects. For example, when you change the location of the phone call icon on your smartphone, it takes you a few weeks to stop automatically going to the old location and training your fingers to move to the new location. But, strangely my brain still hasn't yet associated the Directory Opus icon with file explorer even though it has been a little more than a month. That strongly suggests that the icon should be re-designed. If money is a factor, there are crowd-sourced websites that will design a new icon for you. Or, you can set up a contest that gets current customers involved in designing a new icon.
Besides the inefficiency that results from our brain's inability to associate the current Directory Opus icon with file exploring, there is also another major consideration - aesthetics. This is a consideration that shouldn't be underestimated. A huge percentage of users personalize and buy programs that alter Windows because they want the OS to look more beautiful. Although they won't admit it, they will pay up for a better-looking program or they may subconsciously decline to try out a program because it looks ugly from the start.
Do you know why I am writing this post? I want to purchase Directory Opus but the icon actually makes me not want to buy it. It makes my computer desktop uglier. I know it seems like a petty reason but unfortunately, that's how our brains work. Please seriously reconsider a new icon.
I know that your icon has been used decades so you may be thinking you'll lose a lot of brand equity if you change the icon. I think that's true in most cases but not in this case. I think you'll increase your brand equity because of the substantially increased pull of a beautiful icon vs an ugly one.
TLDR: I strongly urge Directory Opus developers to consider re-designing their icon.