Ensuring deleted data cannot be recovered
 

I have developed an excel/VBA workbook for processing and displaying
sensitive commercial information. I'd like to use the workbook for a number
of clients, but need to ensure that when I pass a "clean" copy to a client,
he/she will not be able to recover information "left over" from a previous
client's processing.

My question is: If I delete information from a worksheet, save under a new
name and then email the new version to someone, how do I ensure that the
deleted information cannot be recovered at a later date, either using built
in tools or specialist data recovery techniques/software?

Many thanks for your help.

Bitter voice of experience speaking: make sure any variables or named
ranges are deleted, and ensure that hidden tabs are deleted or
similarly "cleaned".

If data security is that big an issue, you could convert the Excel file
to PDF format.

Dave,

Many thanks. It was having the bitter voice of experience I was trying to
avoid!

PDF is great for outputs, but I want my clients to use the system to use for
themselves.

Jell


"Dave O" wrote:

If data security is that big an issue, you could convert the Excel file
to PDF format.

Your original post raised a question I never thought about: does
"deleted" information stay deleted, or can it be recovered. I don't
know that Excel operates that way. MS Access creates all kind of
overhead files within a database; if you delete a record or table the
data is no longer available to you, but the file size doesn't decrease
until you compact the database using an on-board utility. Excel
doesn't offer that kind of compact utility, so my *guess* is: deleted
data is deleted when you save the file.

You may want to re-post your question, and rephrase it something very
specific: maybe something like "When I delete something in Excel, can
the data be recovered?" Now that the post is a couple days old it will
get buried in the background- if you repost one of the MVPs will likely
take notice, and answer the question directly.