Had this in the past with an older version. The De-install went fine but the Weather Link folders were still in the program file folder and contained some files from the old version. Since I didn't use WL for any reporting deleting the remaining folders, a restart of the computer and a fresh full install of Weather Link 6.0.5 solved the problem. If you need to keep your data, back up the data folders before deleting everything.
Had something similar with a friend's Epson AIO printer software. After deleting the Epson program folder which wasn't removed by a de-install and doing a fresh install, the scanner portion of his printer started to work again.
