2 GB is a paltry amount and insufficient for normal use.
It is normal for the system to create temporary files that are deleted as necessary; that explains the fluctuations you are seeing. Deletions are accelerated when the available disk space becomes small, and yours is definitely small.
Find out what you can safely delete. Drag unnecessary files to the Trash and then empty the Trash. You need to have free space in double digit GB amounts or you will run into problems as the system desperately tries to find some breathing room. Look for movies that you do not need, downloaded disk image files (likely to be found in your Downloads folder), old podcasts, redundant photos, etc. Empty iPhoto's trash, and delete old emails, especially those with attachments.
Don't wait. OS X will warn you that your startup disk is full only when it's screaming for help, and yours is screaming.
For more ideas read here: Mac OS X 10.6: Increasing disk space
I know I'm on low space at under 10gb and that's easy enough for me to fix.
My problem is that my HD space fluctuates. ie: in the space of an hour it will fluctuate from 2.83gb to zero kb, and then back up again to 2.83gb. During this time period no other activity was performed oher than browsing websites.
I've run anti-virus software and gotten rid of any potential threats or viruses, but the issue persists.
Could someone offer advice based on this?
I just installed it - it actually fixed half the problem and got rid of a virus, so that's not really a good option for me.
However, after getting rid of said virus the fluctuation has slowed down but not stopped.
Therefore, it's obviously not about deleting things from my hard drive - at least not random things anyway - it's something specific that needs to be fixed so that the amount of free space doesn't randomly go up and down.
Any other advice. ie: could it be another piece of software, a browser, a plug in, is there a way to look behind the scenes at how my macbook is running without damaging it (I am a novice to these things after all) so I can fix it myself.
I understand that I don't have a lot of space, but my free space level has been like that for a while and it hasn't caused asingle problem for me yet. So I will be freeing up more space after this, but I'd like to fix the issue at hand first.
Again, I delete things. Again I have never had an issue with having exactly the same amount of space until now.
I'm looking for a slightly different response to "delete things", or "delete anti virus". I'm asking if there is a program I can use to look at how my macbook is running. On a PC I might use Dos Box etc.
I'd like to know what to be looking for rather than just randomly wiping my hard drive.
If you're unable to give me pther advice that's fine but perhaps there is someone else out there that can.