space limitation

i have installed the IDES on my pc.

i am creating lot of master data like materials daily for practising.

Is that consuming the extra space on my hard disk?

And also i want to know if there are different DVDs are available for the same version.i mean if install it from 2 different set of DVDs on two different PCs, all master data in IDES will be same or it may vary?

Also once it is installed, for how many days it will be valid?