error message The type of the file system is NTFS.

hello,
I badly need your help.My problem is that when i switch on my laptop after it has load and before i put my password i get a message on a black screen, the message is as follows:
Checking file system on C:
The type of the file system is NTFS.
Cannot open volume for direct access.
windows has finished checking the disk.

I am using windows vista.Can you please help me to solve my problem.
Waiting for your reply.

regards