OK, late to the party (problem, actually) but, thanks to Vanyun's post, I was able to install the PowerDVD 10 that I downloaded from HP's site. The secret was the comment about vercheck.dll. Here's what I did:
1. Let the downloaded program run as far as it would go (i.e. to silent install failure), then find the folder where it extracted all of the files.
2. Rename vercheck.dll to vercheck.dllx
3. Double-click on Setup.exe
4. Follow the prompts, etc. to success!