Hard drives and the data on them can last quite a long while. I have an old 386 compaq that runs with the same os and data that it had when it was shipped from the manufacturer. Still no problems, on the other hand I have seen people buy hard drives and they die weeks after. It is all hit or miss on how long the bearings inside or other parts will last.
HD failure typically starts with frequent corrupt and unreadable data on the drive. Then Windows will start needing to run Scan or Check disk everytime windows starts if it catches something different. Then clusters will become unreadable and unrecoverable. You might get errors when you try to format. More and more sectors will become unreadable until the drive has a complete crash and the table of contents on the drive is unreadable.
Drives can die slow like that, or BOOM! all at once. depending on the failure.
Check your bios. Most newer MBs can access the SMART data that is provided by the HD internal controller.
In the case of the bios monitor it is a continuous check that doesn't drain any system resources.
SMART looks for things like internal part temperatures going up that indicate increased wear of devices starting to fail.
As for how long HD drives last I have never had one fail in the last 18 years. I end up retiring them and then giving them away because they are too small to bother with anymore.
HD reliability is going to change for the worse with the 7200 RPM and up units though. They are just turning too fast to survive like they used to. 5400 RPM was probably the knee of the failure curve. To get the speed up and the density up they have to start making the moving parts smaller and lighter and require more precision in positioning. That's a formula for premature failure. We do it all the time in high performance airplanes. Note WD dropping their warantee from 3 yeasr to 1 year except on their high dollar stuff.