For the past few days I've got this pop-up bubble warning on my laptop, which comes from the bottom taskbar where the time is displayed. It says: "Windows - Corrupt File. The file or directory C:\WINDOWS\Registration is corrupt and unreadable. Please run the Chkdsk utility."

Is this a valid error message or is it some kind of malware thing on the computer which might be causing it? I'm running Windows XP SP2. I haven't run the Chkdsk because I don't want to cause any damage to the system.