what is 'startup disk'

Today, a message popped up saying that my startup disk is full and needs to have space. I checked the info on Macintosh HD, and I was using 27GB of 250GB. Several minutes later, I was now using 39GB!!!! the only thing I remember doing in between the two messages was downloading podcasts (none that are 12GB!) How do I fix this????

Try a reboot, usually that is the easiest way. Keep us posted if continues?

reboot = restart, right?

yes reboot equal trying restarting your computer. Don't ya just hate the way there's 15 terms for one word... reboot,restart,shut down, etc. haha.

what is going on?

I restarted, same message. I did some investigating. Take a look at the following. Notice the available space keeps decreasing with time. Its like something is continually taking up space. I swear I am not down loading anything, just working on a power point.

View attachment Document1.pdf

Did you recently have this OS installed, or has it ben on for awhile? Do you have anything auto downloading maybe, that you are forgetting, i know that happens to me sometimes where i download a bunch of stuff and forget i put it wherever i put things.

I just got this macbook 4 weeks ago. I am 99% ceartain that nothing is downloading. If you viewed the attatched screen-shots you may have seen that my "used" hard drive keeps increasing. I have cleared several logs and caches and it is still increasing (last checked at 9pm it was 40.75GB). I dont know what to do. I downloaded powermac antivirus and ran it on HD and APPS, but nothing came up.