First of all, if you need help with an error message, please provide the full text of the error message.
If the error has to do with a virtual partition then the likely causes are missing or incorrect drivers. You need a valid VISTA 32 bit driver (WinPE uses vista kernel) for the NIC and also the appropriate SATA driver for the hard disk if the SATA chipset is not natively supported by WinPE.
The link to contact tech support about the available patches is in one of the sticky postings at the top of this forum. You will need details of your support agreement in order to get patches, and these are only made available if the symptoms of your problem match one of the problems that the patches were designed to solve.
Windows 7 doies indeed have two partitions, but making a DISK image rather than a PARTITION image should ensure that you capture both partitions correctly. If you cannot get to the point where the system has booted WinPE and is ready to image, then it's not an issue with Windows 7 but most likely a driver problem. Again, some of the most common topics are discussed in the sticky postings at the top of this forum.