This may sound weird but how do i corrupt a working excel file? I want to test a few new comers for interviews to see if they can fix certain problems so as a start how can i corrupt a working excel file and also have a way of retrieveing it? I dont want to password the file as thats not exactly "corrupting" it.

Thanks

If you have to seek an answer to a question that you'll be asking potential employees, then you shouldn't be asking the question.

Otherwise, you might be able to corrupt the file purposely by using a hex editor or copying it to a dying hard drive, then copy it back.

...or delete the file, overwrite the sectors once or twice, then run an undeleter to retrieve only parts of the file.

As for reversing the process...other than knowing what bits are corrupt via hex editor, it's not so easy, nor should someone be spending a lot of time fixing a file like that.

A better scenario would be to have a good copy of the file, back it up to tape, NAS, or another backup source, delete some key formulas/cells/etc. out of the spreadsheet and ask the person how they would recover the file? They'll need access to whatever you backed up the file to (or have Volume Shadow Copy turned on, and they can recover a good shadow copy).

I couldnt have put that any better if i tried

to the OP: what would be the point of this?

And if they manage to fix them, and you can't (proven by the fact that you're asking), you'll be very embarrased...

GL

I'd suggest asking them if they know how to enable AutoRecover functions/what file types are saved by AutoRecover and where.

Yep you all have a point......due to the politics behind this question i thought to ask as if i dont know anything about it at the same time wondered what other options were available. I do know how to corrupt an excel file BUT "we" were disputing over a few issues again i wont go into this as its all about "company politics" to why i asked the question.

The answer i would have preferred to receive is something along the lines of "its better to prevent than cure" (have a backup than to repair) from the person being interviewed, but was curious what others knew about the subject.

Thanks everyone

My personal opinion, is that UNLESS the job is for a technical consultant in a data recovery or forensics company, the question and the way it is posed would not be appropriate: it would, if answered correctly only discriminate about the candidate "geekness" .

To the question:
Q. Here is a corrupted excel file, what can you do to recover it's contents?

The correct answer is NOT:
A1. Nothing, you should have a backup of it before corruption.
(which noone in his right mind would give in a job interview , as it hints that the Company has bad backup practices or that the interviewer is a jerk)

And is NOT even:
A2. Sure, no problem, let me have a look at it in my hex editor, give me a couples of hours and I'll get the data.
(which is reserved to the very few people that can actually fix a corrupted Excel datasheet with a hex editor, otherwise is either presumptuous or a bluff)

The "right" answer is actually a question:
A3. Sure, how much I am allowed to spend in consulting fees to recover this valuable data? I will start researching a suitable solution as soon as I have a budget.

If you wish to "insist" in the question, meaning it is aimed to test actual knowledge in the use of Excel, I would rather use "address" corruption in formulas, something that an advanced Excel user should be able to fix.

By fiddling with VLOOKUP, HLOOKUP, ADDRESS, INDIRECT functions, and inserting or removing a column within the lookup range, you can easily make an otherwise "perfect" spreadsheet become a mess.

jaclaz

I dont believe theres a right or wrong answer to this, the question is open to discussion..... As i mentioned, to cut the politics out i merely asked the question from a different point.

Sure , I am not pretending to be the one and only truth around , you asked something, and I gave you my personal opinion on the matter, as clearly stated.
Since you asked for it, besides corrupting by hexediting, I proposed a "corrupting complex formulas" approach, that may (or may not) suit your needs.

jaclaz