If the columns go from D right to G, it REALLY sounds like they are hidden.
How exactly did you try to unhide them?

"Brian" wrote:

I was working on an Excel database file for three days, did lots of
modifications and was about ready to finish. It was about 350 lines.
Suddenly I discovered that I lost two columns E & F. I didn't do anything
with those columns, never touched them, tried unhide in format, but couldn't
retrieve those columns. This is very serious. Three days of my hard labour
lost. Am I going to lose my trust in Excel? There's no help on this anywhere.
Please help. I have checked answers from others, about width zero or below
zero and how to correect. But it doesn't help. This requies help from
Microsoft itself. Are you reading this? Can you help?