hdd rule #1 - NEVER rely on any single data storage device
second, all hdd's have bad sectors - thats why they have spares! it wont "kick the bucket" but you can risk data corruption, hdd death will only occur with mechanical or electrical faults etc, so nothing too serious.
Run a tool to gather S.M.A.R.T. information off any hdd and more then likely you will have a "sector reallocation count" more then 0 meaning YOU HAVE BAD SECTORS and they are safely disabled and reallocated etc - nothing to worry about
as for repairing, get "seatools" or "western digital data life diagnostics" (both available and will repair bad sectors for your hdd) and run a test and get it to fully scan the hdd (surface scan), which will find and replace any bad sectors and check the overall health, and also within windows *after* that run, run chkdsk /r to recheck all your data etc