Comments for

Comment from Art campos on 2011-11-20

2011-11-21T00:05:31Z

wow! Leo you are the best

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from bubbles on 2011-11-10

2011-11-11T02:37:45Z

tnx Leo..this article has been very helpful..grateful for this explanation i've been able to save what i seem lost :))

tips to avoid this kind of problem: Don't rename the file just "save as" the file =)

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Mark J on 2011-10-27

2011-10-27T21:47:11Z

@Steven
Some characters such as ?,* or / are not allowed in filenames because they are reserved for system use. ? and *, for example, are used in wild card searches and are disallowed as characters in a file. / is used as a directory separator.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from steven on 2011-10-27

2011-10-27T19:40:17Z

Renaming files-Why cant i rename a file those with " ? ' and some files with little squares "-as part of the name of the file-i get a message which say " you cannot rename this file ........ use ms dos ..... ?Wat does it mean ????

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Amy on 2011-06-29

2011-06-29T13:18:06Z

Thank you so much Leo. This problem has bothered me for forever and I had almost run out of patience. Your explanation not only only told me how to fix it, but it also told me why this was happening which is so important to me. Thank you again for your easy to read easy to understand explanation!

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Ashishparwe on 2011-03-20

2011-03-20T11:07:28Z

hey hi leo

sir i renamed my file from RobinHood.R5.mkvmoviez.com.mkv.001
to RobinHood 1.mkv
and 2 file to RobinHood 2.mkv
but 1st files opens and 2nd doen,t.why

ple help sir.

Without the error message that results I can't say. Realize that the file also needs to actually contain the right stuff (in this case an "mkv" file, apparently.)

20-Mar-2011

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Nam on 2011-01-27

2011-01-27T20:04:20Z

All I can say is "Thank You" Leo! This fixed my problem and so simple if its wrote out:-) for me.
You are now on my FAVs. I really did appreciate the simplicity of it more then anything. O yeah and it fixed the problem.

Have a great day,Nam

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Tina on 2010-04-23

2010-04-23T09:39:42Z

@R: You could also try http://dotwhat.net/ which is pretty useful, thanks for the tip though.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Octav on 2009-08-17

2009-08-17T16:27:44Z

@Alexis Corelis -- For a personal journal? ...Maybe -- and that's assuming whoever wanted to read it had to find it first and was not particularly computer-savvy.

But for anything even slightly more important than that, changing the file extension is more likely to be completely ineffective.

Even on Windows, it's trivial to detect the type of most commonly-encountered files even if the extension part of their filename is missing or corrupted: all one has to do is open the file and try to recognize what's in it -- in many cases, this is as simple as reading the first couple of characters. For instance, an .exe file (or a .dll, for that matter) can be recognized from its first two characters: "MZ". A .zip file will start with "PK". Linux ELF binaries all start with the characters "ELF". All of these are part of the standard that defines how these files are created and used, which means there are very well-known signs to watch for when trying to find out what type a file is.

The main reason against detecting a file type this way (and thus making the extension irrelevant as a way of actually determining a file type) is that opening, say, 1,000 files in the same directory in order to read the first few characters in them is a slow process. Nonetheless, I'm vaguely certain Linuxes (and probably Mac OS X) have been doing it for a while now. On my Xubuntu, I can rename "my-pic.png" to "hahaha" and it still gets properly detected as a PNG image and opens correctly if I double-click it. Note that this is something I can do without any work on my behalf at all -- it's part of the OS itself. And I'm certain the same capability could be built into Windows, at some potential (small) cost in speed.

To summarize: an extension is just part of a file name, which is why it's not likely to be particularly trusted as anything but a first guess at what might be inside. As such, renaming a file to hide its extension does not make it any more secure than moving it into the recycle bin and moving it back out when you want to work on it.

If you have any type of data you truly consider sensitive, use some kind of encryption to hide it behind a password or passphrase only you know. Leo has been recommending TrueCrypt for a good long while, and with good reason.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Alexis Corelis on 2009-08-17

2009-08-17T15:40:12Z

Would this be a backdoor way to make a file inaccessible to someone else? Say I have a journal I keep in Word but don't want anyone else to read it. Can I simply to to Explorer after saving it, take off the .doc extension, then, when I want to open it, go to Explorer, edit the filename to add the .doc? Would this hurt the file any after doing it several times?

It won't hurt the file, but it could be discovered if someone went looking. "Security by Obscurity" is rarely a truly secure approach. If it's important, encrypt it.

18-Aug-2009

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Debbie on 2009-08-12

2009-08-12T13:01:15Z

Thanks for that info... I learned something today! Now why those little pesky things pops up makes sense! I had no idea how to fix it.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Chris on 2009-08-11

2009-08-12T03:05:17Z

For this and the related 3 articles I will buy you a coffee.
The articles solve many problems I have had over time and still get once in a while.
Thanks again Leo

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from Paul on 2009-08-11

2009-08-12T02:18:21Z

Finally you have solved my identical problem which I have been having with file name changing and receiving the same dialog box. Thanks ever so much.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from R on 2009-08-11

2009-08-11T21:40:33Z

I use this site when I run across an extension that I don't know which program it belongs to. It also helps when checking the default file associations, especially after a new piece of software starts changing those associations. There are other sites out there that do the same thing, but this one suits me the best.

http://filext.com/index.php

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from David on 2009-08-11

2009-08-11T20:27:54Z

I have file extensions showing, as it may show up a rogue .exe masquerading as something else.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from claude johnston on 2009-08-11

2009-08-11T18:33:21Z

I found this article to be very informative . It has given me very good information.I had no idea how to make the changes you have just shown.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.

Comment from snickers on 2009-08-11

2009-08-11T15:39:41Z

The idea is obviously to make file management idiot-proof, but it really makes a lot of sense to learn how to recognise and use file extensions. I automatically unhide them on Windows installations. Vista took a step in the right direction by only highlighting the actual file name when renaming.

]]>

A comment on:

Tech Questions? Get Answers! - Ask Leo! ... by Leo Notenboom
Leo's Answers Newsletter - Ask Leo! in your inbox every week.