You can work around this issue by openining the files on a Windows XP machine and saving them in Excel. This will correct the file structure and allow them to be opened on Windows 7 machines.
In a compound file, all sector chains MUST contain valid sector numbers, less
than or equal to MAXREGSECT (0xFFFFFFFA). In a sector chain, the last sector's next
pointer MUST be ENDOFCHAIN (0xFFFFFFFE).
DIFAT Sectors: A special value of ENDOFCHAIN (0xFFFFFFFE) is stored in "Next DIFAT Sector
Location" field of the last DIFAT sector, or in the header when no DIFAT sectors
are needed. Next DIFAT Sector Location (4 bytes): This field specifies the next
sector number in the DIFAT chain of sectors. The first DIFAT sector is specified in
the Header. The last DIFAT sector MUST set this field to ENDOFCHAIN
MiniFAT sectors: If all of the user streams in the file are greater than the cutoff of 4096 bytes,
then mini FAT and mini stream are not required. In this case, the header's first
mini FAT starting sector location can be set to ENDOFCHAIN, and the root directory
entry's starting sector location can be set to ENDOFCHAIN.
Article ID: 2411912 - Last Review: Sep 16, 2010 - Revision: 1