I used the trial version for about 28 days then left it alone for a good while. Now when I try to open it, the msg says there is a file problem and I need to reinstall. But when I try to uninstall this trial version, the msg tells me there is a missing uninstal.dat file and it cannot uninstall.

I want to uninstall this copy and buy the regular software. Can you help?

You could try downloading the installer again and installing over the existing version. That should repair the uninstaller (or simply repair the program itself).

That worked! Got it! Thanks!