Hello wbv,
I see that after upgrading your Operating system to Windows 7, you are now running into problems on the Photosmart C5180. I know you were able to successfully install the updated drivers, were you able to install the HP Software Patch when upgrading to Windows 7?
I also suggest taking a look at fellow community member SuperMario1 recommendation for resolving the Microsoft Visual C+++.
Please let me know if this was helpful, if you require more assistance let me know!
Thank you and Happy Holidays! :)