The Spreadsheets spreadsheet uses the extension ET for its spreadsheets in its own proprietary format.
In addition to the table cell values, an ET file also contains formatting instructions, formulas and possibly also macros. These macros may also contain malicious code, which is why it is advisable, especially for ET files from unknown sources, to subject them to virus scanning before executing the macros.
Most often resolving problems with opening ET files is very simple. Just install an appropriate program that supports such files. All of the listed programs support ET files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of ET files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate ET files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Kingsoft Spreadsheets applications is not on the list, select "Browse" option in order to manually locate the directory where Kingsoft Spreadsheets has been installed.
Sometimes problems with opening ET files may not lie with the application itself, but can arise due to other causes, such as: