If you want some solid advice, don't make your hard drive all one big partition. I highly recommend making a separate smaller partition for the OS (operating system). The reason I say this is, a small OS partition will reduce the amount of time spent defragging. Since the OS partition is the one that has the most changes on a regular basis, it's the one that requires the most defragging. A 2-5 GB partition defrags a lot faster than a 20, 40, 80 or larger partition ever will.
I use a 2 GB partition for 2000 Pro and a 3 GB partition on 2000 Advanced Server. I always move the pagefile.sys to another partition on another hard drive that's on the other IDE controller from the HDD containing the OS partition. This not only will improve performance, it reduces the amount of space required for the OS partition. If you don't have a 2nd HDD, or don't want to be bothered moving your pagefile.sys to another drive, just allow an extra GB on the size of the OS partition to accomodate the pagefile.sys.
With this setup you will of course have to install all software to the second partition. The advantage of this is that after you've installed most everything you want to, or need to, you can then defrag it and will likely not ever have to be defragged again for a very very long time.
My D: drive on this Pro machine has over 11 GB's of data (app's and stored files) on it and after I finished installing everything, I defragged that drive. That was over a year ago and I haven't had to defrag it again ever since that first time. Every time I defrag my OS partition (approx. twice a week) I check the D: drive and it's still less than 10% fragmented.
What does this mean....all in all, it means I spend about 8 minutes twice a week defragging my C: drive and never spend any time defragging any of the other partitions on this computer (I actually have more than just the two partitions. Those are the two partitions on the 1st HDD which contain my OS and all installed software).
