When debugging a macro in Excel, there are a few things to keep in mind. First, make sure that the macro is enabled for debugging. To do this, go to the Tools menu and select Options. In the Options dialog box, select the General tab and check the Enable Macro Debugging option. Next, open the Visual Basic Editor (VBE) by pressing Alt+F11 on your keyboard. In the VBE, go to the Insert menu and select Module. This will insert a new module into your workbook where you can type your macro code.
Once you have inserted a module, type your macro code into the module window. To run your macro, press F5 or go to the Run menu and select Run Sub/UserForm. If your macro contains syntax errors, they will be highlighted in blue. To correct these errors, simply fix the offending line of code and run the macro again.
If your macro does not contain any syntax errors but still does not work as expected, you will need to debug it line by line. To do this, set a breakpoint on the line of code that you want to debug by clicking in the left margin next to that line of code. A breakpoint is indicated by a red dot. Once you have set a breakpoint, press F5 or go to the Run menu and select Run Sub/UserForm to run your macro again.
When your macro reaches the breakpoint, it will pause execution and open the Debug window. From here, you can step through your code line by line using the Step Into (F8), Step Over (SHIFT+F8), or Step Out (CTRL+SHIFT+F8) buttons. As you step through your code, watch the values of variables in the Locals and Watch windows to see if they are changing as expected.
If you find an error in your code, you can fix it and then continue execution by pressing F5 or going to the Run menu and selecting Continue. Alternatively, you can end debugging by pressing CTRL+BREAK or going to the Run menu and selecting End.