Hard Disk Monitoring

here is my story , I have a bad laptop hard disk which got currepted infront of me while windows carshed, tried to repair but diks was loading to certain point and then wouldnt go ahead to repair or install option , so finally pulled it out and connected to another laptop via usb Y cable , windows gives me format option as it couldnt open and recognised as raw( i knew the problem is/was bad crashed or failling HD) tried CHKDSK but windows doesnt have acces to raw partition , tried to format but gives me some error , tried other low-level (0 pass) formating apps but gives me some write-error option at the end after hours spent(:
last resort as i am hopefull , is HDsentinel , bought and installed connected and recognised external hard drive with 1% held and some failure prediction as i dont remeber , it was like raw ....0 predict or something as the disk was raw and all other option was ok in the S.M.R.T option so i ignored and disparatly went for test , chose WRITE-TEST and it's 42hours of surface scan since it started , when it finds a bad sector it takes hours to pass one block as i have kept patience and willing to be more, so, when it detects a bad sector as you know it marks it 'red' it show error: 21 the device is not ready and it was from start when it detected the first one and so far it has detected 3 in red (bad) and 31 damaged in 'yellow' and about 2000 good .
but it has came for the forth bad sector as it didnt finish yet and didnt mark it yet as bad or color, it gave me ERROR: 27 ., the drive cannot find the sector requested.,sector 194392680 . as it is a new error for me
So , would you mind help me please to understand the whole process , are they normal ? is there something wrong ? will these sectors be repaired after it finishes the WRITE-TEST ? it's still going and still some couple hundreds hours to go but i know when it comes out from these trouble sectors it will go faster and time will elaps. and huh, one thing more while test is in progress it is not responding until it refreshes with new thousands of sectors passed , is it normal as well? it only affects HDsentinel software but the laptop working fast and normal. I can see at the top of HDsentinel ( not responding and when i move cusor to those areas it spins as it is in progress , ofcourse it is.
thanks!

Thanks for your message and the experiences.

Basically, if the health is as low as 1-5%, usually the hard disk can't be really repaired.
Such number of problems mean that either the heads and/or the disk platters are damaged (or both).
If one of the heads is damaged, the head may scratch the disk surface when moving, causing more and more problems.

Yes, during the tests, Hard Disk Sentinel tries to force the hard disk to examine the underlying sectors and re-allocate them (by moving data to the spare area and then use that spare area instead of the original sector). If the number of problems is relatively low (in general, the health is 50% or more) this may be completed successfully, but in case of too much problems, it is not really possible (the damaged head even can't use the spare area and/or that area is also damaged or just completely used and there's no room for further reallocation).

Yes, I can confirm that it is completely normal if this reallocation takes _really_ long time, even hours for a single block.
During that time, the hard disk does not respond, causing that the software (Hard Disk Sentinel surface test in this case) seems also not responding.
This is normal, described on http://www.hdsentinel.com/smart

The error codes you mention exactly confirm the above: as you may see, during the test the meaning of these error codes are also displayed, which are:
21 = The device is not ready (because it is busy during the re-allocation procedure)
27 = The drive cannot find the sector requested (the sector can't be accessed because of the re-allocation - or even the administrative areas of the drive is damaged)

According the information received I'm afraid that drive should not be used for data storage.
However, if you can use Report menu Send test report to developer option, I can check the complete status of the drive and may advise.

thanks for your informative reply ,
after being in process all night when i woke up this morning i have suprised with a new error: 1., Incorrect function, this is going for all remaining blocks i guess, hard disk loooks like in idle mode , the light on caddy in which the HD is connected is yellow' and not blinking or red at all ,but sectors are still changing and in what whatever block i click it opens imediately with that error: 1., incorrect function . could you help me explain what this error is for and is that it! the end of my hard disk's life? should i leave it running or there is no point for further repair ?
thanks

In general, during the reallocation process, the drive may not responding (as you could see previously).
In some situations (especially when using an USB adapter, like in this case) the disk controller / the USB chip does not tolerate well if the drive is not responding and because of the timeout, it loses the connection with the device.
If this happens, software accessing further data sectors may receive either error #1 (incorrect function) or the #27 (sector not found).

After disconnect, power off and on again and reconnect of the drive, it may work again - for some time, until a such timeout condition happens again.

You may try to start the test again (or adjust it to start on a specific block to continue where the previous test failed) but because of the high number of problems and the low health value, I do not really think the drive could be fully repaired.