I don't know if you ever solved this or not, but I have had the same problem. These are a couple of things that have worked for me (no one solution works every time, but hey, I'm too cheap to buy another program):
There were two old dll files in the Powerdirector program, so I replaced the comctl32.dll and msvcp60.dll with newer versions found in the windows system 32 folder. This worked to get the program opened and working at the time, but lo and behold, later that same month it stopped opening again. Then I...
...noticed that when I opened task manager the pdr.exe process was running, even though it did not show that the program was running, and when I ended that process in task manager, the program opened again. But again, the program stopped opening for a time, and so today I...
...found a file called pdr.exe.manifest on my hard drive, and when I right clicked and told it it "open with" the "VideoEditorTL" program, Powerdirector opened.
I think maybe I'll just leave it open forever at this point!
I'm not all that computer savvy, but these things have worked for me so far, and maybe someone will answer my query as to why the pdr.exe.manifest file opens the program.