Why is my HD clich¨| it is using 2 times the amount of space it's in reality using?

I bought a 500GB external HD by Western Digital and I am at the emergence stages of ripping all my CDs to iTunes. iTunes tell me that my current library (which is being stored on the WD HD) is 2.24 GB. However, my WD 500GB HD, when I right-click and check the properties, tell me it has:

4.48 GB used.

I've checked the size of the report that is storing the music, and it say 4.39 GB (im guessing the other .whatever GB is software for the HD). Why is it truism it's using double the amount? Or is iTunes reading it 1/2 off? HELP PLEASE I am going to be storing video on this also, and I can't enjoy this much space missing for long.

Why is my HD clich¨| it is using 2 times the amount of space it's in reality using?

there are some virus that multiply your used space within your drive by creating new files out of sight, scan your drives with an updated antivirus, or if it newly happens near the files created with confident program maybe it is out of action like it should be abandoned apartments for sale