> For the complete documentation index, see [llms.txt](https://excelhelp.windhamlabs.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://excelhelp.windhamlabs.com/getting-started/installing-excel-lab/activate-add-in.md).

# Step 3: Activate Add-in

Once Excel Lab has been installed, you will need to activate the add-in. To do this in Microsoft Excel

(1) Open Excel

(2) In Excel's menu, select **File -> Options**

(3) In Excel's options menu, select **Add-ins**

(4) At the bottom of the dialog, click on **Go... (Excel Add-ins)**

(5) An Add-ins window will pop up, click on **Browse...**

(6) Select the Excel Lab add-in file at the following location

     `C:\Program Files\Windham Labs\WindhamXlsLab\application\WindhamXlsLab.xla`

(7) Click OK. The add-in should be activated.