I followed the steps in this question. The registry location was different, and in fact didn't contain "Hewlett-Packard". I searched and replaced this in the registry (RegisteredOrganization, Company, CompanyName, RegCompany keys where applicable), and I deleted the dat file, but the splash screen still displays the incorrect data.
However, Help -> About... displays the correct data.
How do I get the splash screen updated?
I'm running Win 8.