Yes, it needs ALOT of space on your hard drive. You have to INSTALL the game in order to play the game. The CD just contains the installer.
Try cleaning the CD. if that doesn't work World of Warcraft gives you a chance to download the full client for free (requires a World of Warcraft Account). Also, check if you have enough space on your hard drive.
It is highly doubtful that you will be able to install let alone play World of Warcraft on the Eee PC 900 laptop as the hard drive space is barely big enough to fit the game, let alone the space needed for the operating system.
You will need approximately 15 Gigabytes (GB) to install World of Warcraft.
The best place to put World of Warcraft would be on your internal hard drive, however you can also put it on an external hard drive, or another type of removable drive...as long as it can be read and wrote to.
Depending on the configuration of the computer and the speed of the hard drive. It is always best to install World of Warcraft to the main internal hard drive.
Its all depends on your internet connection and how new (or old) your computer is and how much free space is available on the current drive you are installing it to.
My "World of Warcraft" folder takes about 15GB on a 350GB drive with 2 partitions. It took about 20GB to update my Lich King to Cataclysm; 5GB was temp space and returned after the update. I would make sure I had at least 40GB to make sure I could get updates (which sometimes measure in the GBs.) The newest version of the streaming system is better than earlier versions, but still needs the temp space.
No plans for a warcraft 4 have been announced. It has been stated that World of Warcraft is technically their "warcraft 4" because it has been ( and still is) continuing the storyline of the warcraft universe.
If it has enough space
The creators of world of warcraft were just continuing in their success in the creation of other , very popular video games just as Diablo I. World of Warcraft was supposed to be their prized jewel, and in my opinion, it still is.
15 gigabytes of free hard drive space is recommended, I believe. My program is currently using 17.2 gigabytes of my hard drive.
You will still have to pay the 15$/mo. -- If you do not want to pay a store for the installation media, you can download the installer form the World of Warcraft site. But like the previous answer, you still have to pay the monthly fee. You also have to pay to start the service and for the expansions.