Explorer shows the wrong amount of disk space

hi,
i have Dell Home Inspiron 1420 laptop T2390 3GB 160GB 14.1in WXGA DVD+-RW,installed windows xp sp2,when I right click on C drive, Properties it says: 85.4GB used, 57.7GB Free But when I select all files (including Hidden files) and Propeties it says: Size 46.2GB , Size on disk 46.5GB.i am not getting why it is showing less amount of space,I've run chkdsk and done a system defrag. I've gone into the windows disk cleaner utility and deleted most of the temporary files, including the hibernation files.What has happened and what is the solution?Can anyone help!!!

The Setup program is unable to recognize volumes larger than 1 GB; therefore, a value of 0 is reported from the operating system during the search for available disk space. Setup changes the 0 value to 999,999K to make sure that enough space is reported for Setup to continue.

Maybe defragmenter just does not display it properly. Try to estimate occupied space folder by folder.However, modern hard drives usually come with installation software that gets around that. Options include: (1) At a command (DOS-like) prompt run "CHKDSK C: /F", assuming that the partion in question is called C:\. This requests a full check/fix of the disk, but XP will first say something about not being able to do it now, and do you want to do it on the next re-boot. Say Yes. Reboot. (2) Check with the hard drive manufacture and see whether there is something special one has to do for large drives. (3) Try upgrading to a newer BIOS, if one is available. (4) Try splitting the drive into two (or more) partition of no greater than 32Gig each. I recommend Partition Magic.

hi,
And, I am sure you are aware that a 160GB drive will not show as 160GB in Windows.Manufacturer sizes against actual sizes are measured differently.
A manufacturer will claim 160,000,000 bytes is 160GB when in actual fact it is 160,000,000,000/1024/1024/1024 = 149.It is also very likley that although you are only seeing one partition, there is often a hidden partition (for recovery) taking up some more space.You can look at this in: Right click My Computer > Manage > Disk Management.