Patrick,
If you're not on 7.2.0, you can try upgrading to the latest version of PSM, available from our web site.
You might also want to try manually installing the prerequisites, most of which can be downloaded from Microsoft's web site:
Microsoft .Net Framework
- Version 2.0 SP1 on Windows 2000, XP and 2003 Server.
- Version 3.5 SP1 on Windows Vista, 2008 Server and 7.
MSXML 4.0 SP2 Parser and SDK
VCRedist (Visual C++ 2008 vanilla)
Access Database Engine
Try manually installing those and make sure the installation completes correctly. Lastly, you might want to reboot your system if you haven't already done so.
Start with that, and let us know how that goes!
Regards,
Raphaël Lalonde Lefebvre