if you install windows, the first thing you're going to want to do it turn off (or at least shrink the page file, this will give you a little more disk space. (~1GB)
then you want to tell it to never be able to hibernate, since the hiber.sys file will take 1GB of space.
you also want to go through the options when installing windows and tell it to not install pretty much everything, don't play solitaire? then why install it.
not disabled? then why install accessibility tools like screen magnifier
never use word pad then tell it to not be available. and so on until you've trimmed just about everything out of the system.
without a lot of the system components you'll also find that that the updates that you apply will be lessened too. (but try slipstreaming your OS to include most patches etc so that there is less need to patch anyway).
since you'll have crippled the system by turning off or reducing the page file, then you'll want to turn off as many services as possible, whilst still letting the notebook actually run.
then you'll have a not too shabby system for playing about online with.
the other route is just just use a reduced linux distribution. -but if you've never used linux this may have a bit of learning attached to it.
Damn small linux is very good, but getting rather old now.