You can't fix physical bad sectors and must remap to avoid them and this is
low level and tedious. You can do it from Linux or Windows but must work
from an unmounted partition or drive. There are utilities that you can
download or use ones that come with drives which are the best tools for
this, IMO. You can fix bad logical bad sectors which are software based, but
you should find out which they are first. There is a good discussion here
and some tools that you might use:
ask.metafilter.com/.../How-best-to-respond-to-a-bad-sector