Hdd with 30% health and 74 bad sector

[Chiborio]

I do apologize if there is already a topic about this.

My friend's laptop couldn't start up windows.
He decided to format and reinstall windows.
After the install of windows, he was able to start windows but it keeps freezing or very slow.
Soon after, the laptop was unable to start up windows again.
After some diagnostics, still couldn't identify the issue.

So I use another the hard disk to see if the problem was the hard disk and seems it was. now its running Windows fine.

Now i formatted the problem hdd and checked with HDS.
On the report i have 100%performance, 30% health and 74 bad sector that were moved to the spare area.

My assumption is that the bad sectors are now moved to the spare area so that it won't be used in the future.
At this point,

1)Could I still use the Hdd for main/primary hdd for laptop? ( put it back on laptop and install windows)
I understand that the hdd is not strongly reliable.

2)Is it better or must to buy new hdd and use the hdd for external storage for some non important data?

I know that there isn't really right answer for this but Please let me know you opinions.
Thank you in advance.

[hdsentinel]

Yes, the most important is to know that the "bad sectors" reported in the text description are no longer used by the hard disk drive: they are already fixed (reallocated). It means that they can't be read/write in the future, a special (reserved) spare area is used for all reads and writes targeting those bad sectors.

This means that the hard disk capacity remains the same (did not decrease) and in an ideal world, there should be no problems with the hard disk drive: the hard disk reallocated some sectors and now all sectors (the original good sectors plus the ones from the spare area) are fully usable.

Manufacturers (exactly because of the above) allow some bad sectors - and there are no big problems until their number is relatively lower and the status of the hard disk drive is stable. This is why then Hard Disk Sentinel displays that you may not need warranty replacement, but the most important is to verify the hard disk drive with intensive test methods, to confirm if the status is stable or if there may be other problems - as I suspect there may be more sectors which need to be examined and re-allocated to prevent their use in the future.

Please check:
http://www.hdsentinel.com/faq.php#health
and
http://www.hdsentinel.com/faq.php#tests

for more information about this situation.
And if the status is stable (the Disk -> Surface test functions would not show any problems), then yes, it is possible to use the hard disk - but generally for secondary storage, not to store important data on it, based on the current health.

So the question is
- did the hard disk found all bad sectors and fixed them by re-allocating?
- are there any further problems with the drive (eg. weak sectors, spin retry issues, etc.) which may cause problems?
- are there any areas of the drive which may be very hard to access and are there damaged sectors?
(as displayed for example at Support -> Knowledge Base -> Hard Disk Cases -> Bad Sectors ( http://www.hdsentinel.com/hard_disk_cas ... ectors.php )

So I'd recommend to perform the tests available in Hard Disk Sentinel to reveal and fix the problems reported about the hard disk drive and if things seem fine, you may continue using the drive. However, I'd recommend constant monitoring and immediate backup upon any new (even minor) problem, even 1% decrease of health to avoid problems / data loss.

[Chiborio]

Thank you.
I've tried the intense test for random seek test, surface test, and extended self test but no problem/error found.
It seems working fine as a external hard drive but when i used it for internal/primary for the laptop then the hard drive seems not working proper again.
The laptop works fine with other hdd.
The problem seems its the hdd but I'm not really sure anymore.

[hdsentinel]

It is possible that there are some incompatibility issues with the laptop (for example its controller, chipset) and the hard disk.
Or maybe the laptop has some troubles in delivering enough power to this hard disk for proper operation - but an other hard disk may work better as internal hard disk. Sometimes it happens that a hard disk work correctly in a different environment (for example when you use as an external hard disk).

If you can use Report menu -> Send test report to developer option, I can check the complete status of the hard disk.