September 2, 2010
Ok, the title may sound bad, but I have nth hackerish in mind, so please keep reading.
A couple of days ago, I wanted to add the "" to the registry of Win7 64 bit. When I tried to create the respective D-Word, I was offered the choice between a 32-bit or a 64-bit one. That's where I canceled the whole procedure, as I wasn't sure which one to choose. I did a search, but not even [url=http://support.microsoft.com/kb/967715:wax0jln7]MS official article[/url:wax0jln7] offers any direction (part "How to disable or enable all Autorun features in Windows 7 and other operating systems").
On another occasion, I stumbled upon instructions on how to disable the "PIn apps to the Taskbar" through the registry. In this case the D-Word to add was 32-bit, which makes no sense to me as we're talking about a 64bit OS.
So, in general:
1. In which cases does one choose a 32-bit D-Word and when a 64-bit one?
2. Are there specific aspects/ points one takes into consideration in order to make the correct choice?
3. Does anyone know of a reliable guide about this?
By the way Dave, nice articles on introducing the registry.
I am human
Hey FD - I am far from expert in this field but I can tell you that the DWORD (32-bit) value and QWORD (64-bit) value has nothing to do with the installed operating system.
It actually depends on the length of the value you are wanting to enter, this from Wikipedia:
[quote:1qrw58v4]Some computer architectures define the term dword (double word) to be a unit of data that is twice the size of a word. The x86 platform originally had a word size of 16 bits (2 bytes) and that usage of the term is confusingly retained even though the actual processor word size is now 32 bits or even 64 bits. In that platform, a dword designates a 32-bit (4-byte) unit.
Similarly qword (quadruple word) is a unit of data that is four times the size of a word. On the x86 platform, this unit of data is 64 bits long because the definition of word on an x86 [/quote:1qrw58v4]
Dave and Ziggie will be able to explain this much better than I......stand by!!
September 2, 2010
Thanks for the reply, but it only got me more confused. You see, your excerpt says
[quote:3fkxlh9t]qword (quadruple word) is a unit of data that is four times the size of a word. On the x86 platform, this unit of data is 64 bits long because the definition of word on an x86 [/quote:3fkxlh9t]
but when right-clicking on the right pane of the registry in Win XP 32bit, I was never offered a QWORD, nor have I seen it or DWORD(64-bit) before. But then, I never had a 64bit OS before, so I assumed it's OS related. If it's not, it makes even less sense to me.
I am human
Hey FD - Okay, I suppose it does have something to do with the OS, but only remotely. (I did warn you I was far from expert on this subject )
My understanding is this: The 32-bit arhcitecture will not handle 64-bit units of data, that is why in a 32-bit OS you will not see the option. A 64-bit OS however is backwards compatible so you can use either 32-bit or 64-bit units of data.....hence the option.
So the answer to your question: [quote:3voppvsv]In which cases does one choose a 32-bit D-Word and when a 64-bit one?[/quote:3voppvsv]
The choice you make really has nothing to do with the OS, i.e. 64-bit OS does not necessarily mean you must choose the 64-bit option. That choice depends entirely on the unit size of the data.
Unfortunately our dear Dave is slightly under the weather at the moment and unable to respond but I've also notified the mighty Zig and he will certainly know a[i:3voppvsv] lot [/i:3voppvsv]more about this than I.
August 11, 2011
This is not my field of expertise either. I tend to ignore the registry unless I'm really bored. Nine times out of ten when a problem requires me to edit the registry to solve it, I just wipe / reload the machine and/or restore to my last image. ~shrug~ I'm lazy.
From my quick research (yay Google) - Jim is correct, it has more to do with the length of the value you are adding and less to do with the OS. The OS however, has to know QWord exists. It appears the QWORD option was introduced in Windows 2000. Depending on which version of Registry Editor you run (There is a 16 bit, 32 bit, and a 64 bit version apparently), the QWORD option may not appear.
Confusingly, the internet seems to say that it is and isn't limited to just 64 bit OS's.
So to answer your original questions:
1) Choose 64 bit value when your value is greater than 32 bits.
2) Solely based on the length of your value. Obviously, 64 bit values take up more memory than 32 bit value. This doesn't come into play except in very large registries.
3) Not that I know of.
September 2, 2010
July 27, 2017
The 64 bit computers can run both 32bit programs and 64 bit programs. 32 bit computers cannot run 64 bit programs, because the bit sizes are fundamentally different. Latest Laptops with pre-installed Windows are usually x64 i.e. 64 Bit, old Desktops and Laptops could be having Windows x86 which means 32 bit.
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