How to delete files from Mathcad15?

What does you mean by delete xlsx files? Do you mean references?

Helena Jacobsson Sandlund wrote: Can I use VBA script to delete xlsx files from inside Mathcad?

Yes, you can. Use a scriptable compononent - typically the button or tickbox control, right-click on it and choose Edit Script from the context menu. Then write your VBScript to delete the files. You can set up the control so that you can hard code the list into the control or create an array of files names in Mathcad and pass that array to the control (as an input).

Stuart