First off, try holding the shift key while double clicking the desktop icon for PSP X3 (if you don't have a desktop icon then find the exe file that launches the program, it won't work off of the start menu shortcut). This will reset the program to defaults. If that works skip the rest.
If you're really stuck you may need to reinstall. To do that you'll need a clean uninstall. I use Revo Uninstaller
http://www.majorgeeks.com/Revo_Uninstaller_d5706.html but there's others that use other procedures. Corel's official procedure can be found in this thread
http://forum.corel.com/EN/viewtopic.php?f=56&t=38064
When you re-install PSP X3 you need to turn off any and all security programs, turn off UAC, and run the installer as admin with Windows XP compatibility.
When you get it installed don't let the program download the updates itself. It will just grab the last update and that will likely break the install. Disconnecting from the internet completely is what I did.
If all of that fails try creating a new account in Windows and try again there. You shouldn't have to since you have a fresh OS install, but that's the final desperate try. It might work. If it does work and you don't want another account on your computer you should be alright to delete the new account.
