.I04 File Extension

It's an ISO mds disk image split with DVD Decrypter (to avoid problems with some file systems with large file sizes). You must use the mds file to burn/mount the image or convert it to an iso.
Use sfv file to check integrity of the files to burn (mds file + i00 file (i01 file, i02 file, i03 file, i0[number] etc).

 

Here are some programs to use mds files with differents O.S. (It's possible do it in different ways)
Windows: DVD decrypter or imgburn, Alcohol 120% etc.
Linux user's: use mdf2iso
Mac users:
Rename the files with extension i00 to i0x as follows:
- filename.i00 => filename.iso.001
...
- filename.i05 => filename.iso.006
Then use the program Split and Concat to join the files and make an ISO.

If you don't know how to burn the files. Use each program's help guide.

How to open:

Use e.g. Alcohol 120% to open files with i04.

How to convert:

Most disk image formats can be nowadays converted to standard ISO format, however conversion between various formats is typically possible. Your best option is typically some disk image management tool with broad format support, for example ISOBuster. For general information try to look at:Basic info how to convert disk images