>>>>>Sometimes getdiskserial fails. It means that returns empty string. It depends on the user. But with the same user (poweruser), in different computer (in the same network) does the job. I can have the correct string, changing the user (as administrator works), but the poweruser has ( or so it seems) the complete control. I do not understand this behavior.
>>>>>Sombody can help me to solve this problem?
>>>>>Thnx in advance
>>>>
>>>>Don't use diskserial for copy protect. Use ethernet ID for that. That's a more reliable way.
>>>You mean the MAC address, I suppose.
>>>
>>>Peter
>>
>>Yes... Cetin said that "MAC address can be changed, too", but it's hard to do for an average user.
>
>I really don't know ethernet ID. Is it easy to use and where to search ?

I can't remembered who gived me this function, it works good:

Local pGUID,rGUID
Declare integer CoCreateGuid in 'OLE32.dll' ;
  string @pguid
Declare integer StringFromGUID2 in 'OLE32.dll' ;
  string rguid, string @lpsz, integer cchMax

pGUID=replicate(chr(0),16)
rGUID=replicate(chr(0),80)

If "5." $ OS() && 2000/XP
  Declare integer UuidCreateSequential in 'RPCRT4.dll'  string @ Uuid
  lcMacAddress = iif( UuidCreateSequential(@pGUID) = 0 ;
    and StringFromGUID2(pGUID,@rGUID,40) # 0, ;
    substr(StrConv(left(rGUID,76),6),26,12), "" )
* VFP7
*  CLEAR DLLS 'UuidCreateSequential' 
Else
  lcMacAddress = iif( CoCreateGuid(@pGUID) = 0 ;
    and StringFromGUID2(pGUID,@rGUID,40) # 0, ;
    substr(StrConv(left(rGUID,76),6),26,12), "" )
ENDIF
? lcMacAddress
*VFP7
*CLEAR DLLS 'WNetGetUser','GetComputerName','CoCreateGuid','StringFromGUID2'