how can i deal with this problem for installing R2012b?

product dependencies one or more of the following products are required to proceed with the installation: MATLAB 8.0(not available)

you must select a folder where at least one of these products is installed or select these additional products for intstallation

[Jan]

I guess, that this is the appearing error message. You forgot to mention, when this message appears.

It seems like the message is clear. So what exactly is your problem?

[Tariq]

I believe he is referring to this error during installation, after the licensing step is complete.

Answer 1

[Walter Roberson]

You could get that error if you attempted to install a toolbox without having the base version of MATLAB for that toolbox installed.