One of your disks needs to be checked for consistency

Hi

I have got two hard disk on my desktop one of them is called C for OS XP SP3 and other is called D for program files and Data

Recently whenever I restarted my PC I would have been experiencing the message below

Checking file system on D :

Type : NTFS

 
One of your disks needs to be checked for consistency. You may cancel the disk check, but it is strongly recommended that you continue.

 
Windows will now check the disk.

 
CHKDSK is verifying files (stage 1 of 3)

File verification completed

 
CHKDSK is verifying indexes (stage 2 of 3 )

File verification for completed

 
CHKDSK is verifying security descriptors (stage 3 of 3 )

Security descriptors completed

 
 
After that I could not write the whole message

What could be causing this problem ?

Thanks