How To Make An Iso Of 2 Gb On A 650 Mb



Hey guys!

I don’t understnad why sometime ISO files of 650 MB can contain over 2 GB of data?

Is some body can explain to me how to make a such of CD-rom. Someone told me, some technicians use a kind of compression to make this kind of CD-ROM.



You cannot put 2GB of raw data onto a 650 meg disc, it’s just physically impossible.

You can use compression such as ZIP ACE and RAR to make a file much smaller, but it all depends on what is being compressed.

Typically text files can be compressed well because they contain a lot of repetitive chains of letters and numbers (it’s because data is repeatitive that compression works, but that’s another story).
The same could be said of ISO’s, as long as the data inside the ISO contains the right type of data a 2 gig image can fit inside a 650 meg compressed file.


For me, it is possible cause I got this kind of CD!!! 6 Windows XP in 1 CD the total is over 2 GB.


Perhaps that is a DVD .ISO, not a CD ISO?


First off I see Dee-Ehn has edited your first post. You should have taken this as a sign that you were posting something wrong. Obviously he thought that the rest of your question was a valid one and could stay.

Now onto your second post. Obviously since you have taken notice of the first and read our rulez you will now that things like warez and ISO are not allowed on the forum.

6 Windows XP in 1 CD is not a genuine CDs licensed by Microsoft. Therefore it falls into the before mentioned category.

Dee-Ehn gave you your one chance by editting your first post. Please don’t make the same mistakes again.


I thought an explanation of how this is done would be useful.

Microsoft make CDs which appear to have a lot more than 650MB on them. For instance, the MSDN CD for Windows 2000 has the Pro, Server and Advanced Server files all on the same CD.

What is actually happening is that the directory indexes have been built in a non-standard way so that where the same file exists in the three versions of Windows, the different indexes actually point to the same file on the disk. So the majority of files on the disk, which appear to be present in three copies, are actually only there once. However, routines for displaying the size of the contents of the disk don’t have any way to know this, and so add the size of the files in three times. Hence the disk appears to contain much more than 650MB, but in reality it does not.

The warez CD mentioned in the thread presumably uses the same technique.

I am not aware of any generally available tools to make CDs in this way.