Dave

To lock workbook or worksheets go to Tools>Protection>Protect Workbook or
Protect Worksheet.

They each have different functionality.  You're probably after the sheet
protection.

Neither of these will lock the workbook from opening, but can protect from
modification.

Gord Dibben  MS Excel MVP

Just to add to Gord's suggestion.

It kind of sounds like you want to protect some cells from being
overwritten--maybe formulas or headers/description cells.  And still allow
yourself to update other cells.

If that's the case, select the cells that should be able to be changed.
format|cells|protection tab|Uncheck Locked

Then Tools|Protection|protect sheet (don't provide a password).

But be aware that there are lots of things you can't do on a protected
worksheet.  You may need to unprotect it to do somethings--then reprotect it
when you're done.

Sat, 2 Jun 2007 20:17:41 -0500 from Dave <djbahb@dcwis.com>:

With the workbook *not* opened in Excel, open an Explorer window(*),
right-click on the file, and select Properties. Check "Read Only" and
click OK.

(*) File Explorer, not Internet Explorer. If you don't know how to
start File Explorer, press the Windows and E keys simultaneously if
you have a Windows key on your keyboard; otherwise open My Computer.