OK, I got this figured out now. IIRC, I had to re-create time sheets when I went from Win 7 to XP and now I know why.
First, you have to enable show hidden files in your win 7 machine. Here are instructions for doing so. Show hidden files & folders in Windows 7
HourGuard splits timesheets into a totally separate folder on the Win 7 machine. It also portions out the Accounts, Tasks, and Options folders into another separate location.
HourGuard itself resides in the folder listed in the migrate help here on this forum, but none of the data is in this folder.