found this on the Russian try this:
Fatal error. Unable to install updates.
This problem can occur due to lack of space on the system disk. The default is C: drive.
Please check the free space on the system partition, the minimum required for the installation of updates about 2 GB of free space.
And also recommend that you check the free space partition that has the game client, such as drive D:.
In Windows Vista and Windows 7, this problem may occur because of lack of rights to overwrite files.
Try to run the game launcher as an administrator to do this, click on the shortcut, right-click in the drop-down menu, click "Run as Administrator".
If running as administrator did not help, it is recommended to reinstall the game client to another partition, if any.
Install the game client should be in a folder does not contain Russian letters, as well as the installation path to the folder with the game must not contain Russian letters.
Please be informed, in the case of installed versions (skins, sights, lights, etc.), we can not guarantee full or partial performance by a game.
In order to completely uninstall the game client from your computer, follow these steps:
1) If the game client has been downloaded and installed on your computer:
For Windows XP: You need to click: Start-> Control Panel-> Add or Remove programs list that appears, select the game client World of Tanks-> delete;
For Windows 7 (Vista): You will need to click: Start-> Control Panel-> Programs-> Programs and Features in the list that appears select the game client World of Tanks-> Delete.
After that, download the file from our website -
http://downloads.wor...es/wot_pref.zip
Unzip and run the bat-file, it automatically removes the remaining part of the game.
2) If the game client has been copied from another computer:
For Windows XP, 7, Vista: You need to go to the folder that contains the game client, example: "D: \ Games", find the folder named "World_of_Tanks" (you have the folder name may be different in the cases to make any changes) click on the folder, right click, select "Delete", then confirm the deletion of the folder.
After that, download the file from our website -
http://downloads.wor...es/wot_pref.zip, Unzip and run the bat-file, it automatically removes the remaining part of the game.
After removing the need to restart your computer.
Install the game client you can pre-download it on our site:
http://worldoftanks.ru/ru/update