The Solver add-in isn't enabled by default in Excel. To find it, you need to first ensure it's installed and then you'll find it on the Data Tab.

1. Check if Solver is Installed:

* Go to File> Options> Add-Ins .

* At the bottom, under "Manage," select "Excel Add-ins" and click "Go."

* If you see "Solver Add-in" in the list, it's installed. If not, you'll need to install it (see step 2).

2. Install Solver (if necessary):

* In the Add-Ins dialog box (from step 1), check the "Solver Add-in" box and click "OK".

3. Locate Solver:

Once Solver is installed, it will appear on the Data tab in the ribbon at the top of the Excel window. It's usually towards the far right. You might need to adjust your ribbon display to see it.

If you still can't find it after following these steps, search for "Solver" in the Excel search bar (usually found in the upper right corner).