Victor Nijegorodov wrote: Just for a test: what will happen if you call mCSVListCtrl.DeleteColumn(0); from anywhere but from this MyClass::OnLvnColumnclickList(...) message handler? It's the same. I think I'll have to go for the dummy left column idea some of you have suggested - maybe I'll use it to number the rows which might be quite nice anyway. Thanks again for all your replies.

Frankly, i don't know, sorry... :( > The problem with computers is that they do what you tell them to do and not what you want them to do. < > If it doesn't matter, it's antimatter.<

I finally worked it out. You were right about access priveleges etc. On quitting my app would try and update a data file in the app's own program folder - hence the error (unless the folder's priveleges had been manually changed, or UAC turned off). I turned off UAC within about 5 minutes off getting Vista, so didn't realise what was happening. Doesn't this make developing software for Vista a lot more complicated? Is Windows 7 the same? Thanks again GC

and without a project and a solution. Let's call it Parformatter (Parser + Formatter). :) «_Superman_» I love work. It gives me something to do between weekends. Microsoft MVP (Visual C++)