problems running HDD Diagnostic tools on certain pc's

I fix plenty of other peoples pc's and run into the following issue quite often:

Often when I try to test a suspected faulty HDD i go and run the manufacturers diagnostic tools on it, as is normal practice.

only problem is that much of the time, running a bootable ISO cd version of the diagnostic tools can be problematic.

For example, samsung HDUTIL, or seagate seatools- if you run their offical bootable ISO's you often get these "out of memory errors" or "bad command or filename" type junk when its booting.

On the occasion that I can successfully enter Samsung or seagates utilities sometimes the harddrives are not detected. Sometimes I feel as though they aren't detecting the SATA drives in particular... in fact i am certain i haven't had a non detection issue of a PATA drive before, although the boot up problem can occur on them too.

I'll only have booting problems or detection problems like this on about 10-20% of systems i run the ISO's on. Surely this must be a problem for many.

My own personal pc cannot run the bootable iso for the samsung drives in it, so i cant test my own pc. Sometimes I might have to hook a drive up to another machine and try it there.

So if you have had these common boot fails with the major hdd diag tools, do you know what might be causing this kind of stuff ? I assume something in the BIOS must be preventing them from loading directly during boot.

the second issue is as to why many SATA hdd's aren't always detected in multiple systems with the diagnostic tools. sometimes i have to resort to third party testing tools to see and test them, which i dont trust as much as the proper manufacturer tools