There is not enough of disk space. No matter how large hard disk you get, it will get filled up eventually.
After having only 20MB of free space on my C: -drive, I finally take a closer look at the utilities that can point me the directories and files that are reserving the most of the disk space. I found this great utility:
Good looking, graphical, Java -based, free and easy to use utility to show exactly what are the directories and files consuming the most of your disk space.
After scanning thru my C: and D: drives I could purge almost 13 GB of meaningless files.