9 GB Update after installing the game from DVD?

[Dakku]

As the title is saying I installed "Left 4 Dead 2" from the DVD, but it still wants to download 9 GB. But let me first tell you how I had to install the game:
I'm from Germany and as some of you maybe know in Germany games are often censored. Because of this I use to buy my games in retail in Austria. So I did with Left 4 Dead 2 and tried to install it but alway got "Connection timeout". I maybe have to say that I didn't bought the European-, but the UK-Version. I tried to install it while connecting by proxy-server and steam finally started installing the game.
Well, it actually not started installing, it started downloading the game. 9GB of data it said. Because my internet connection is not that good I looked for a way to install the game by DVD and installed it by typing

"C:\Program Files\Steam\Steam.exe" -install E:

in command line. E: is the DVD drive i was installing from, but I think you got that.
So steam started installing from the DVD saying it installs about 4.2 GB.
After the installation was finished I got to the steam library, but steam still wants to download 9 GB. It says 3.4 GB are already downloaded, but i think these came from the DVD, so there need to be downloaded 6.6 GB.
By googling i found out that this is a kind of steam glitch or bug and now I want to know, if it's fixable and if it's even a bug or it actually needs to download these data.
I would be very thankful, if anyone of you could help me.
Sorry for any spelling or grammar mistakes I maybe did, but I'm not a native speaker, so don't be that rude.

[`Binks ᕦ(ˇò_ó)ᕤ]

there has been a lot of content added to l4d2 since the release 4 years ago. for comparison, my l4d2 folder has 53,000+ files and is 14.4 gigs
you are probably downloading all of the new updates, patches, content

[Pingas]

What Professor Probe said. Lots of content was added since the game originally came out.

[Dakku]

Thank you for answering.
I hope, you're right. I looked in my Left 4 Dead folder and i only found folders and subfolders, no data. Data was only in the download folder. Somehow the download process jumped back to 839.5 MB, wich is quite confusing, because the Left 4 Dead download folder has a size of about 12 GB, don't know how this happened. I hope it's not downloading the cutted german Version. I think I will have to do an overnight download and see how far it got tomorrow.

[For Unlawful Carnal Knowledge]

Yes the dvd version is not an updated version. The dvd might be behind about 60 or 70 updates some are over 2 gbs big. When l4d2 came out in 2009 the size was about 7.8 gb's well over the years and all the updates that 7.8 gb turned into like 15 to 16 gb's. The reason it downloaded from steam and not installed the dvd version is cause the dvd version was older then the one on steams servers so steam was downloading the newest version for you instead of installing the old version. Since the cd keys are made different for each region of the world your cd key would let you download the uk version not the german version. But i will let you know one thing the german version makes up with no gore and no bodys laying around since they disappear as soon as you kill them is you get an extra gun and a knife other regions don't get. The german version gets to use this gun right off the bat no cheats or modded server needed http://i.ytimg.com/vi/2KcMtEy1dDc/0.jpg or it might be this gun http://imageshack.us/photo/my-images/148/mp5a5tokyomarui.jpg/ i forget which one is in the german version while people with modded servers can unlock it for other regions to use it or anyone in the world can use it by using a console command to get it.
Also be glad you don't have max payne 3 when it was released it was 24 gb's big and now after updates its over 35 gb's big lol

[Dakku]

Thank you for answering, Chucky. It's really nice to see, how gamers from all around the world stick together.
I know that every gore or splatter effect is missing in the german version, that's why I bought a foreign one.
As I understand you it's downloading the UK version. I can't check wich version is downloaded, because it only made it to 1.7 GB this night. I begin to hate steam more and more, because every game that needs it involves a lot of waiting and rage because of bad download speed.
Do you know, why the download folder for Left 4 Dead 2 has already a size of around 12 GB and the amount of files didn't change, though the download proceeds?