what OS are you running right now? depends on what you're trying to install... check the installers guide, you can see it there..
There is an average volume for any operating system and it's about 4 gb as well. Hope that your free space will be enough for this and Windows XP, Vista or 7 be pleasant for you.
If you install XP without Service pack then it will take 1.41 GB with SP1 1.9 GB With SP2 7 GB approximately. with SP 3 it takes 3.2 to to 3.3 i have no idea about window 7 or vista because i am using only XP SP3.
Good collection of information. I have installed XP SP1 and it has taken only 1.41 GB which is so good for me in this PC.
if you are installing windows then it will take approximately 20 GB space and other then window its depend upon that software, so first check the whole size of that software then u will be clearify, that how much space will get that software.....