Deleting the 'unused' portion of an Excel worksheet

I accidentally underlined a row, rather than a series of cells within a row.  Now my Excel spreadsheet thinks all those empty, but underlined cells to the right of my data are "used cells".  I can't figure out how far right the spreadsheet goes, so I can't GoTo the far right.  (1) How can I find the actual far right column in my spreadsheet, whether used or not? and (2) how can I delete these columns, where a row is underlined, but has no data in them?  MerRob54

Perhaps I'm missing something… but I think you are saying that you put a bottom border in all the cells on a line.

Why don't you just remove the bottom border for the whole line, and then put it back on only the cells you want it?