>>>Hard disks can fail. In an app I'm working on, I use Winmgmt Service to get the CPU serial number and OS serial number, but I must confess that I haven't tried it under various permissions.
>>
>>It would be interesting to see whether this works in Windows 7.
>
>Be my guest!
>
>
>-m.
>
>

>
>*==============================================================================
>* Method:			iApplication.GetCPUid
>* Purpose:			Gets the serial number of the CPU.
>* Author:			Hammack Development Assoc.
>* Parameters:		None.
>* Returns:			Character-string alphanumeric processor ID, else "" if
>*					not able to determine or error condition encountered.
>* Added:			08/27/2009
>*==============================================================================
>
>LOCAL loWMI, loCPUs, loCPU, lcResult
>loWMI = GETOBJECT("winmgmts:")
>IF VARTYPE(loWMI) <> T_OBJECT
>	RETURN ""
>ENDIF
>
>loCPUs = loWMI.InstancesOf("WIN32_Processor")
>IF VARTYPE(loCPUs) <> T_OBJECT OR VARTYPE(loCPUs.Count) <> T_NUMERIC OR loCPUs.Count <> 1
>	RETURN ""
>ENDIF
>
>FOR EACH loCPU IN loCPUs
>	lcResult = loCPU.processorID
>	IF VARTYPE(lcResult) = T_NUMERIC AND NOT EMPTY(lcResult)
>		lcResult = TRANSFORM(lcResult)
>	ENDIF
>
>ENDFOR    && EACH loCPU IN loCPUs
>
>RETURN IIF(VARTYPE(lcResult) = T_CHARACTER AND NOT EMPTY(lcResult), ;
>lcResult, "")    && end iApplication.GetCPUid
>

I used this, it works slow some computers so I removed.