Electronic publication (EPUB) is a file extension that stands for the Open Publication Structure eBook file. EPUB is a well-known and freely accessible eBook standard, so the majority of EFUB files you meet will be of this format. EPUB is made for a reflowable content, which means that an EPUB reader can correct TXT for a display gadget.
In addition to the problem described above, i.e. the lack of the appropriate application to support the .EPUB file, there may be several reasons that cause problems with opening and operation of the data format:
A quite common problem is the lack of application in the appropriate version. Even if you have an application, with the help of which you should open the .EPUB file, you may have a problem with it because of its version. Perhaps in previous versions the application has not yet supported the .EPUB file, so download the update and check again.
If you have already installed the appropriate application, and it is the correct version, the file may not open correctly, because the operating system does not have information that this program supports the file. So you need to "show" which program the computer should use. To do this:
It also happens that the file you want to open is corrupt and therefore there is no such possibility. In this situation, you should find its different version, or ask a person from whom you got, to send it again. You can also try to find more informations about this file extension here.