Uncovering and Removing Links

@Kevin
I haven't tried the add in but Louise's link worked fine for me, just make sure you don't pick up the fullstop she had at the end.
http://www.manville.org.uk/software/findlink.htm

Update
Starting anew
Paste of Columns doesn't create a link.
Paste custom Style Formats doesn't create a link.
Paste Conditional Formats does create a link.

Editing out the Conditional Format link doesn't remove the workbook link indication.
Deleting the CF containing cell doesn't remove the workbook link indication.
All Undo till prior to paste doesn't remove the workbook link indication.

I have tried all the points in these notes and still have external links indicated.
Does anyone have the info referred to in the Louise link. My tries on the link failed to complete.

Check your Conditional Formatting as I have deleted external references from in there.

When dealing with complex workbooks, tracing the web of dependencies among cells is one of the most important, and possibly difficult things we have to do. To be clear, as Microsoft stated in https://support.office.com/en-ie/article/find-links-external-references-in-a-workbook-fcbf4576-3aab-4029-ba25-54313a532ff1, a link is a reference from one Excel workbook to another - an "external reference". The article shows how they can be contained in formulas, defined names, objects (like text boxes or shapes), chart titles, and chart data series. As Pieter pointed out (and has driven me crazy any number of times) they can also be found in data validations.

Allen's Edit Links suggestion is a good way out of this mess, but only when the target workbook has the same worksheets/tabs as the current workbook. What Edit Links does is allow you to select one of the external workbooks, and then find and cycle through all the references in the current workbook to that external workbook, and replace them. It has 5 options:
- Update Values: Excel will reach into the external workbook and refresh the values in all formulas and other places that reference the selected external workbook: this makes sense only if the external workbook isn't already open as otherwise these values are made current with every recalc.
- Change Source: Changes the workbook referenced by the formulas, defined name definitions, etc. If, as Allen implied, you choose the current workbook to be the new target workbook, all of those links become simple ones (i.e., WorkSheet!Range without the [WorkBook] part). Otherwise it just swaps out the [WorkBook] part of the reference with one pointing to the new target workbook. Note that, either way, it does this only where it can: the new target workbook has to have a worksheet with the same name or the link wouldn't make any sense. If it's able to change all of the references to the selected external workbook, it will remove this link from the Edit Links box. If not, both the original and new target workbooks are still in the list of Links.
- Open Source: This just opens the external workbook
- Break Link: This replaces all the references to the external workbook with the cached corresponding values.
- Check Status: Will update the "Status" column in the selection box.

Here's the fun part: Change Source reliably changes references in formulas (where as I said above the new target has a WorkSheet with the same name), and is probably also reliable with defined names, objects, chart titles, and chart data series. But it definitely doesn't touch data validations. If you have any of those, the old external workbook name will stay in the Edit Links selection box after a successful Change Source, and you'll have to chase them down and "heal them" by hand.

This whole topic is made more confusing because "link" has two different meanings: it could either be an individual reference in one workbook to another (a formula, defined name definition, chart series definition, etc.) or a member of a list of external workbook names that Excel maintains as a property of the workbook. Edit Links, for instance, clearly populates its selection box by walking down the list of external workbooks in the current workbooks Links property. But it doesn't directly add or deleted items from that list: Excel will remove an item from that list only when it knows there are no more links to the external workbook, or add one when the first such reference is created. From VBA, you can walk down that list of property values and change one of them - but this triggers the same action as doing Change Source from the Edit Links dialog box, so it removes the old reference only if when it has cycled through all the current references it was able to update all of them.

By the way, it's tempting to think that the formulas used in Conditional Formats could cause the same problem as do Data Validations - but "You may not use references to other workbooks for Conditional Formatting criteria." So that's one place, at least, where you don't need to look for problems.

I have found the following link really useful in finding and removing links to other Excel spreadsheets.

http://www.manville.org.uk/software/findlink.htm.

This add-in will find all links and either list or delete them for you.

With the use of Excel Tables becoming more common and hence the use of structured references, doing a find on square brackets gives too many false positives. You are better of searching for the "xls"

Thanks for this useful Excel tip! One more type of difficult to find links I come across sometimes is in cells with data validation. If you have cells that have data entry restriction set to "List" (referenced to a range in the worksheet) and you copy them from one workbook to another, the data validation still refers to the range in the original workbook. Remove or change this by removing or editing the data validation of the copied cells.