Hard Disk Monitoring

When I run the surface test I get the error message:
unable to lock the disk for exclusive use. Are you sure you want to test it anyway?
Disk:? error: 5 Access denied.
What does this mean?
This is disk C: my boot disc and its a Samsung HD103SJ and I am running Windows 7 32 bit.

This is completely normal.

It means that because of a running program (or the operating system in this case) the drive can't be locked for exclusive use during the test.

For write-tests, it is required that other programs (and the OS) should not be active on the appropriate drive.

For read-test, the exclusive use (lock) is not required, you can continue (ignore) without problems (without any risk).
Just then you may experience some darker green blocks on the disk surface map because when the running OS reads/writes any files, the current block may be accessed a bit slower. If this happens, a repeated test may confirm if there is a real issue with the surface or if that block was slower only because of the background activity of WIndows.

OK thanks for that.
One question, if I perform a "Short SEl-test" I get the message "Test Failed by Read Element" "Response 0*79" what does this mean?

It means that the drive has some problems and because of that, the internal "short self test" function of the hard disk can't be completed.
In general this is not a big problem - most cases this happens even if the hard disk is almost perfect (for example if only 1-2 minor issues found with that and the reported health is as high as 95-99%).
In this case (as described in the Help), the Disk -> Surface test options may be better as they can examine the complete disk surface and reveal, fix the problems.

I had also this problem but now i am happy.i have solved It by hdsentinel's instruction.

thanks hdsentinel ,

Same thing. The instruction helps. Cheers on that!