Hi Wm,

I'm sorry to hear that you're having trouble unhiding columns in Excel. Here are a few things you can try:

1. Make sure you're selecting the correct columns: If you're trying to unhide columns F through K, make sure you're selecting columns E and L before you try to unhide them. You can do this by clicking on the column headers for E and L while holding down the Ctrl key.
   
2. Check for frozen panes: If your worksheet has frozen panes, you may not be able to unhide columns. To check for frozen panes, go to the View tab and look for the Freeze Panes button. If it's highlighted, click on it to unfreeze the panes.
   
3. Try using the Home tab: Instead of using the Window tab to unhide columns, try using the Home tab. Select the columns you want to unhide, then go to the Home tab and click on the Format button. From there, select Hide & Unhide Unhide Columns.
   
4. Check for protected cells: If your worksheet has protected cells, you may not be able to unhide columns. To check for protected cells, go to the Review tab and look for the Protect Sheet button. If it's highlighted, click on it to unprotect the sheet.

I hope one of these solutions works for you!