1.) Select the cells you want to "lock", right click, chose format cells.
Once the Format Cells box comes up, select the Protection tab, chose
"locked".
2.) Select the same cells, go to the Home tab, Cells group, click on Format
button, select Protect sheet. Type in a password if you like, (you may leave
the other defaulted options selected), click "OK", (if you input a password
you will need to confirm it).

Now your cells are "locked". To "unlock" them. Select the same cells, click
on the same Format button (as before), click on "unprotect sheet", then type
in password (if you have one).

Note: once you have unprotected the worksheet you will need to re-protect
it before saving/closing the workbook.

"terryc" wrote:

I conditionally formatted a range of cells so that a cell changes color if
the content =x. How can I lock the cell if it contains an x?

The scenario is an employee schedule. I put an x in the cell of days they
can't work. But I've deleted the x by mistake and scheduled the employee. I'm
hoping the color change will help me but would like the cell to lock if I put
an x in the cell. Then I'd need to know how to unlock an individual cell if
the employee changed their mind.

I've seen posts about conditional format\custom but can't find it in 2007.
Thanx