Q: "I upgraded from an old version of BigOven, and now cannot see my old recipe data."
A: Not to worry -- BigOven does NOT delete recipe boxes unless you specifically tell it to during the uninstall/reinstall process. Chances are, in upgrading, BigOven is simply looking in a different file location.
Specifically, the NEW location (after BigOven 1.8.6) is the Windows-XP-Guidelines location "Shared Documents" (which is literally "C:\Documents and Settings\All Users\Documents") rather than "My Documents" for your My BigOven Recipes folder. Having this folder in "Shared Documents" also lets other users of the same XP machine share the recipe box and shopping list data, which is very useful in a household. So that's our new, default location and will be for the indefinite future.
Here's how to move all your "old" (good) data to the new location that BigOven expects:
1) Close out of BigOven
2) Use Windows Explorer to locate your "My Documents" folder. Notice the file dates on some of the recipe boxes in the "My BigOven Recipes\RBox" folder. Is this your correct data?
3) If so, copy the "My BigOven Recipes" folder FROM your My Documents folder ON TOP OF the new, expected location for BigOven 1.8.6 and later: Shared Documents\My BigOven Recipes.
See this post for more information on "Where BigOven looks for files".