Dword or Qword?

I have a Win 7 PC using 64 Bit.

When entering a new name in the Registry and the particular tweak that I am reading says to create a new Dword, instead should it not be a Qword - which is 64 Bit entry?

That would depend on the length of your entry. You would only need to use a Qword if your entry calls for it. Dword and Qword has nothing to do with the bit version of Windows.

To make things simple a Qword is four 16-bit words not one 64-bit word. This is why a Qword can exist on a x86 machine.

Read more here - http://en.wikipedia.org/wiki/Dword#Dword_and_Qword

thanks for the explaination

but for example, if I wanted to create a Dword entry on regedit with the corresponding hexadecimal value of 5GB, would it accept it and show 5GB on the add/remove programs? Cause I tried that but the maximum value it shows is 3.99GB so i was wondering if changing to Qword it'll show 5GB.
Thanks

That would probably depend on the program reading the registry entry. I wouldn't know what the results would be by manually changing the value from dword to qword. My guess would be if the program was designed to read a qword value, that would be the value found in the registry. You can try because it is possible, I simply can not say for sure it will work.

Please be careful, editing the registry can render an operating system useless.

yeah.. I've tried it and didn't work and didn't show anything at all. But thanks for your reply.

I wanted to get more detail/clarification on Dword vs Qword when you say it depends on the length of the entry - is this like how many characters are in the subkey or like how many characters are in the decimal value of said subkey or is it something else entirely?

To give an example when you find windows specific tweaks that changes how windows 7 behaves or some speed items up - here is a example link to a quick google search I did that hopefully better explains my question http://www.wincert.net/forum/index.p...bnail-preview/ This link is just one example.

So to make sure I am asking the correct question....when performing OS tweaks like this - If you are running 32bit windows - do you select Dword? and if you are running 64bit windows can/should you select Qword? Or if it more the length of the entry - how does one know when looking at the tweak of which type of key to select?

REG_DWORD - 32-bit number

• The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory.

REG_QWORD - 64-bit number

• A 64-bit register can store 2^64 (2 to 64th power) = 18,446,744,073,709,551,616 different values.

I think there are other uses for DWORD and QWORD but you get the picture. A QWORD is simply twice the length of a DWORD, looking at it from a length stand point of how many bits the value was stored with.

I wish I could tell you all the ins and outs without any doubts. This is about the extent of what I understand myself.

I understand the math behind 32/64 bit processors and the powers 2^32, when you do the math that is why 32bit windows can only use up to 4GB of Ram and why 64 bit can use so much more...but this info does not address my question....maybe I am not making myself clear or am asking the wrong question.

Maybe it would help if I knew why you were asking.

What is it exactly that brings this question to the table?
Are you working on something that requires the use of DWORD or QWORD?