Hello. I'd like to speak with you today about creating a compressed folder in
Windows 7. Before I do that, however, I'd like to talk a little bit about
compression. First of all, as you know, everything on the computer is
represented in bits. Everything is reducible to zeros and ones -- and by
"everything," I mean text files. I mean programs. I mean audio. I mean video. To
give you an example, Paint stores images as bitmaps. Each canvas is made up of a
certain number of pixels across and down. Each pixel can be a single color. One pixel
can be red or it can be blue, but it can't be partly red and partly blue. If
you're dealing with a monochrome image such as we have here, you really only
have two choices: black or white. Two choices can be represented by a single
bit; for example, zero might represent white, one might represent black. So in an
uncompressed format, ordinarily this might be stored as lots and lots and
lots of zeros to represent all of this white, still more zeros more zeros more
zeros, then three black or three -- we've got three black pixels here, so we've got
three ones, a lot more zeros to represent all this white. Five ones in a row to
represent this next line down -- five black squares, lots and lots of white squares,
lots more zeros and so on. Imagine, however if instead of having to store 00
000 -- a thousand zeros followed by a few ones followed by a thousand more zeros
followed by maybe 25 ones, imagine instead of having to take all those bits
for that, you had some special way of saying repeat 0 a thousand times.That
special way of representing a thousand zeros would take less space than
representing the series with a thousand bits. This would be an example of a very
simple compression algorithm using this special repeating symbol. Now
in actual practice, the compression algorithms are far more complex, but this
gives you a feel for how it might be possible to represent the exact same
information in less space. Windows makes it possible to save files of various
types using less space with its built-in compression. You can create a compressed
folder and then put files into it and the files -- depending on what is in them --
may very well take up less space; it might be just a little less space, it might be a lot
less space. So for example this "Psych notes" is nineteen thousand bytes, more or
less, of text. To create a compressed folder, I could right-click on an empty
spot in this pane just as I would to create a regular folder, and -- again, just
as with a regular folder -- I can go to "New," but if instead of choosing "Folder," I
choose "Compressed zipped folder," I will create a compressed folder. I can then
give this compressed folder any name that I like, such as "Notes" (because i'm
going to be putting my notes in here). I click outside of that area to deselect
"Notes." I'm then going to right-drag and drop my "Psych notes" on to my "Notes"
folder. By right-dragging rather than dragging, I can choose whether I wish to
copy the "Psych notes" or to move them. "Copy" is bold, so that's the default. In
point of fact, I do wish to copy; I'm going to choose "Copy" here. Now you'll
notice that I've got my original "Psych notes" that is 19 kilobytes. My compressed
folder is 11 kilobytes; it's a lot smaller. If I open up my compressed
folder, I can see a "Psych notes" listed in here, and I can double click on the "Psych
notes." When I do that, you see that Word opens in read-only mode; that's one of
the disadvantages of compression -- we don't just compress everything that
we're working with partly because if we want to make any sort of changes,
we're going to be having to extract the file from our compressed
folder. We're going to have to decompress the file -- restore to the original size --
make changes, and then we could put the modified file back into a compressed
folder, if we wished. The other downside of working with a compressed object is
that it's going to take a little bit longer to do any sort of processing, but
if I do wish to extract this file again, if I just want to open it I could choose
to open it here. If I come up to the folder above my compressed folder so I
can see the compressed folder, I can right-click on it and choose to "Extract
All." I'm going to be asked where would you like to place the extracted file,
and by default it will be placed in the same folder as the one that
contains the compressed folder. So I'll leave the default here. I'm not going to
browse to any different location, and I don't want to see the extracted files
when complete. I'll just say "Extract," and now you'll see we have a new,
uncompressed folder called "Notes." The compressed one has an icon
that has a zipper on it; regular folders do not have the zipper. If you are
showing your file types, compressed folders have the file type or the
extension of "zip." Uncompressed ones don't have any visible extension. So what
are the main points with creating a compressed folder and using it? To create
it, you can right-click on a blank part of the window-->New-->Compressed (zipped)
Folder. Give it whatever name you'd like. Place in it anything that you'd like to
have compressed. When you wish to make use of the items. if you just want to see
the contents, you don't want to make any changes, you're not doing anything all
that extensive, you can work with the compressed version. If you do wish to
make changes, you do wish to do extensive processing, you're going to be
needing to right-click on the folder and choose "Extract All."
If you don't wish to extract everything, another thing you could do is you could
come into the folder copy the item that you wish to extract. If I had 10
different items in here and I only wished to extract the "Psych notes," I could
right- click on psych notes and choose "Copy," go wherever I like to paste it,
right-click and choose "Paste." Now I already have a file of this name -- my original
file-- in here, so Windows has asked me what do I want to do: Do I
really wish to replace the original with a copy, do I wish to say "Don't copy," or
I'm going to copy but keep both files,
and in theory I should be seeing a second copy in here. I'm not sure why I'm
not, but in theory I should be. Okay I'm not sure why I hadn't been seeing the
second copy; I just refreshed the screen and now you can see the second copy.
Thank you very much. Goodbye