I'm with excelledsoftware in thinking that Excel's autosuggest doesn't keep a list anywhere but in the worksheets themselves—so that if all instances of 'cJ' are gone from the worksheets, then it shouldn't be offering it any more. But here are some ideas; and frankly they're all thin, but nothing else is working so I'll toss 'em in the air and see whether any of them fly.

1) There are other Find options we haven't considered. Notice the one labeled "Look in:"; on my machine, that option uses "Formulas" by default, and I have to change it to "Values" if it matters.

As I understand it, the "Formulas" setting causes the Find option to look in what you see in the formula bar at the top, the "Values" setting to look at what's displayed in the cell itself. If you type "CJ" into a cell, then "CJ" is both the formula and the resulting value. But if you were to put this in a cell:...then that's the formula (and it contains the value 'cJ') but the cell's value is "John". In that case, if you tell Excel to look for 'cJ' using "Look in: Values", Excel will tell you it can't find it even though that mixed-case string exists in a formula.

On the other hand, if your formula is "=VLOOKUP(A2,OtherTab!B:E,4,0)" and that lookup is finding 'cJ' somewhere, then searching Formulas on this worksheet will come up empty for 'cJ' but searching Values will find it.

2) The above is a stretch, but this one may be a better chance: Are you looking Within:Sheet or Within:Workbook? If you looked in just the current worksheet, could 'cJ' be in some other sheet? I think Sheet is the default setting; try looking again using Workbook.

3) Notice also the option labeled "Match entire cell contents"; if it's checked, then the search will find a cell if it's just 'cJ', but not (again) if it's "McJohn" or even 'cJ ' (note the trailing space).

4) One last faint glimmer of hope: I'm not even sure this is a possibility, but I wonder whether the 'cJ' is still there because Excel doesn't know yet that it's gone from the worksheets. Is there any chance that the workbook has been open since you started this thread? I mean, do you leave your machine on, and the workbook open, when you go home at night? If so, maybe—just maybe—if 'cJ' is nowhere in the workbook, and you close the workbook and open it up again, this'll go away.

Or, of course, you could always resort to the panacea of PCs: reboot, and see whether the problem disappears .