"I didn't give enough space for a growing system."
operating system? vista, XP?
you can move various folders from the root drive to another partition to give you more space. click here
there is also no need to take the install option of most software as c:\program files, you can install programs to another partition.
Vista has its own built in partition manager XP will need another program but it is dangerous to mess with the op system partition BACK UP FIRST.