You can't just randomly move content for any installed program and then expect the program to know where its resources have been moved to.
Since you did that and ran PD19, it sounds like PD19 saw that all the content was gone and removed those folders from it's resource list and didn't restore them when you moved the content back.
At this point, the best thing to do is to follow the steps in this
discussion to create a symbolic junction from where the files are currently on your C: drive that points to the new location on your D: drive. Once that's done and your content is on the D: drive, you'll need to uninstall then reinstall PD19 and then download and install the latest patch.
If you don't feel comfortable making these changes, maybe ask a tech-savvy friend or go to a local PC store that offeres tech support services.