To prevent users unhiding sheets protect the workbook. From the Menus
ToolsProtectionProtect Workbook. Add a password.

To have certain cells on a sheet unlocked and others locked, select the
cells you want to unlock (by default all cells are locked). Then
FormatCellsProtection Uncheck Locked. Then ToolsProtectionProtect
Sheet. Add a password.

Note this will prevent the average user from making unwanted changes.
Anybody a bit more determined will be able to crack the workbook and
worksheet protection passwords.

Hope this helps
Rowan

Lee Harris wrote:
Is it possible to hide sheets but prevent users from just unhiding them from
the Excel main menu? either they can't do it or need a password for example?

Likewise, what is the correct way to lock off cells in different sheets so
that only certain cells accept data and the user can't just unlock the other
cells

cheers