Excel

The fix can be a little weird and non-intuitive. To unhide column A, or any set of columns on the far-left, select column B and, without letting go of your left mouse click, continue dragging to the left until you're over the left side of the column. Once selected you can let go of your mouse button. Then, right-click column B header (any selected column header, actually) and select Unhide.

The trick is to ensure you're selecting the hidden columns, which is difficult because, well, they're hidden. Another way would be to use the Name box to select the range. You need to be careful though, because you could name a range. Since "A" is a valid name for a range, you could actually name column B to a range name of "A". This would make things *very* confusing. If you were to use the Name box to select columns A through B, you would need to click in it and type "A:B" which is a valid range *reference*. If a reference is typed in that box it will go to, or select, that range if it can. Then you would right-click any selected column as described above and choose Unhide from the menu.

HTH