When installing product on Windows XP OS you recieve error:
"A file that is required cannot be installed because the cabinet file C:\Documents and Settings\dell\Application Data\ParallelGraphics\RapidAuthor\install\disk1.cab has an Invalid digital signature. This may indicate that the cabinet file is corrupt"
This is a result of certification path that was updated on October 10th, 2010 to include two intermediate CA's. Not all client machines or devices have the G5 Root certificate installed.
There are two options to resolve this matter:
1. Enable Internet Access and needed certificates will be uploaded from web.
2. Download needed сertificate from here and install it on your machine.