Your HDD is already running non-stop for ca. 2 years! Thats incredible and so much! Because this is your D: drive I wouldn't get now in panic. But you should change your HDD in the next months (my recommendation). The values are not "so" bad.
I recommend installing Hard Disk Sentinel, as it give a clear explanation about the state of the drive and also gives an estimated remaining life.
If you install it, post a screenshot here.
Is there any thing I can do about this problem and what exactly does this [ "They may be remapped anytime in the later use of the disk" ] mean?
Hard Disk Sentinel provide a detailed explanation of weak sectors on their website.Is there any thing I can do about this problem and what exactly does this [ "They may be remapped anytime in the later use of the disk" ] mean?
Because weak sectors may not indicate real failure of the hard disk drive, they are not counted as seriously as real bad sectors or other attributes / issues.
... in most cases the weak sectors do not indicate real problems with the hard disk.