ComputerID in Qt - windows

Question

Well, i just need a way to get Windows ComputerID (Hardware based), an ID that doesn't change, or something similar, unchangeable unless you do hardware changes in your PC.

Answer 1

Qt does not provide such a functionality. All you can do is to calculate such a value from the existing hardware, like the CPU, the installed hard disks and/or the MAC address. None of these approaches provides an fully satisfying solution to your problem.
The use the CPU for a hardware based ID you can use the Assembler command CPUID: http://en.wikipedia.org/wiki/CPUID, http://www.sandpile.org/ia32/cpuid.htm provide some detailed information.
QByteArray CPU_Vendor_Name()
{
char Vendor[13];
_asm
{
// EAX = 0: Get CPU manufacturer
XOR EAX, EAX
CPUID
MOV EAX, EBX
MOV Vendor[0], al
MOV Vendor[1], ah
SHR EAX, 16
MOV Vendor[2], al
MOV Vendor[3], ah
MOV EAX, EDX
MOV Vendor[4], al
MOV Vendor[5], ah
SHR EAX, 16
MOV Vendor[6], al
MOV Vendor[7], ah
MOV EAX, ECX
MOV Vendor[8], al
MOV Vendor[9], ah
SHR EAX, 16
MOV Vendor[10], al
MOV Vendor[11], ah
MOV Vendor[12], 00
}
return QByteArray(Vendor);
}
This will return "GenuineIntel" for all intel processors and "AuthenticAMD" for AMD processor. This is quite useless, but with other parameters in the EAX register you get detailed information about the processor (detailed model, features, etc.). You can use this to calculate an ID (for example: SHA(Vendor, Model, BrandID, CPUCount)) etc. But bear in mind that the same processor will always result in the same ID.
You can enrich your ID with the MAC address (= SHA(Vendor, ..., MAC)), but the MAC address can be changed, although it's not very likely that the average computer will do that frequently.
In case you want to implement some sort of copy protection, remember that every copy protection can be cracked, so you shouldn't punish your users with a very sophisticated protection that limits the use of your software for them.

Answer 2

I realize that this is an old post, but I came across this document and had to post it because it explains the CPUID and the process of extracting the CPU information from the chip. Not that #Wolfgang Plaschg was in any way incorrect. As a newb, his answer made some sense but there was a slight level of abstraction that I wasn't seeing through at first. Maybe this can help other newbs too... This is the document from Intel:
http://download.intel.com/design/PentiumIII/applnots/24512501.pdf
if the link fails or is no longer available, search for the Intel AP-909 Application Note. Also, this link is of some help too:
https://software.intel.com/en-us/forums/topic/308483
Enjoy!