You have to do a repair installation of X3 in order to teach windows to use it for your CorelDraw and photopaint files.
Find the X3 entry in control panel > programs and features (or add and remove programs if it is XP) and double click on it to begin the install, then you should be able to select repair.
That's the best way to do it, because there are a lot of settings that need changing. But if you want to do them one at a time, then the "open as" can do it for a particular file type -- there's a checkbox at the bottom something like "always use this ..,." which you need to turn on before accepting the program. But I think you will find too many other settings also need updating.
What tool setting is missing in X6?
In Photo Paint X3, the airbrush tool has a setting for transparency and another setting for ink amount. In X6 the ink amount setting is missing and nobody seems to know why (I've asked everywhere I can think of, including on Corel's two Facebook pages.) Without the ink amount setting I can't get the fine mist I like to work with, so I had no choice but to go back to X3.
Thank you Harry. That worked indeed! (I feel like I should be using a more recent version, but what else can I do?)
I only have X6 at the office on one system any longer and have X7 everywhere and no X3 at all however let me ask this, do you work in CMYK or RGB?
Most of the bitmaps I work with are either RGB or grayscale. Does X7 have the ink amount setting?