Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
How to Optimize Space on A Macintosh Computer
There comes a time with almost all the computer users when you feel the hard disk is too decked to store more multimedia files or crucial data. This is the time you want to create more disk space and ensure that you don’t have to give up on the extra data.
The process, fortunately, is as easy as for those who use a PC; however there are certain MAC specific steps involved that we will discuss in this article.
(You will need a Macintosh G4 or a higher system running Mac OS 10.4 or other higher versions for this.)
1. The first step is to launch Macintosh HD and move to Movies. Browse the listed data for files that seemed cool and funny at some time but now don’t interest you much. Move these files to Trash. Keep in mind video files eat up a lot of space.
2. Go to Music/iTunes shows and other multimedia files folders and delete the ones you don’t like now. Keep in mind, if it comes to making a choice between few files, look at the format. If you bought them through iTunes then these files would be compressed and won’t take much space. However videos downloaded from YouTube and heavy in other video sites tend to be size. Having said that, delete iTunes files as well if they don’t interest you any more.
3. Delete old files that you don’t need any more, be it old word documents or snaps. Most of us have the habit of uploading anything that we can, only to find later the need for more space. Try to stay proactive in terms of what to keep and what not to.
4. Locate and delete the localization files. There are many programs that install foreign language help files for the international users. For such cases, you can download software such as DeLocalizer and run it. Many a times, it can free up as much as 1 Gigabyte of space. DeLocalizer will let you pick the language you want to keep the help files in and delete the rest.
5. Browsing history can eat space as well. So simply launch the browser and delete the browsing history.
6. If you are running Leopard, launch it to check the history and delete the past items. From finder window, it says Today, yesterday et al.
7. Look for cache files and delete them. For Safari, Tap Cmd-Opt-E and you are done. For other applications, use cleaner applications such as TidyUp or Maintenance or if you want to do it alone, simply do it by going to Macintosh HD/ Users/(your name)/Library/Cache.
8. Launch Finder and open Applications. This is the folder that lists all the applications you use. Look for those that you don’t use any more. Delete these applications with software that removes all the related files and folders for that application. You can try AppDelete for this.
9. Look for locked files in Trash and get rid of them.
10. Try plugging in the spare hard rive you have and transfer all the redundant data on to that. This way you won’t lose any data and would create more space on the Mac as well.
11. Go to the Disk Utility. Here pick your hard drive and move on to erase. Click erase free space
12. Keep in mind that the music files get duplicated into Music/iTunes/iTunes Music when you add them to iTunes. So delete any downloaded or transferred files from the original folder. This will add more space and organization.
Keep in mind, Trash holds a lot of space as well so empty that.
During this entire exercise, keep in mind not to delete files that you use or need. Do not delete essential programs. Do not change your hard drive either and don’t reformat the disk or else lyou will lose everything.