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I've got a Dell Precision T5400 here, and had to go into the BIOS and flip on VT before I was able to run VMs. While I was in there, I found that several other features were disabled (even really important ones like Execute Disable).

Why would a PC maker disable capabilities of the hardware they ship by default? (Particularly when they leave the (worthless) serial and parallel port controllers on by default)

(This isn't specific to Dell -- that just happens to be the box I'm currently working on)

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In some cases its to protect the hardware, like for overclocking. You can do it, but it can void the warranty on some devices. – soandos Jun 1 '11 at 2:18
@sonandos: Overclocking is a different case. xD and VT are CPU features fully supported by the chipset and CPU maker (Intel in both cases). It's just odd that the default setting is to disallow use of those features). – Billy ONeal Jun 1 '11 at 4:55
@closevoters: How is this "Not a real question" or "Subjective and argumentative"? I'm not ranting here -- I honestly don't care what the defaults are so long as I can change them. I'm asking why that's the default though -- seems PC makers are selling themselves short by doing this. – Billy ONeal Jun 1 '11 at 5:00
@BillyONeal it could be construed as subjective because we can't really objectively say why PC manufacturers choose to do something, we can just speculate. That being said, I think it's a reasonable question and wouldn't personally choose to close it. – nhinkle Jun 1 '11 at 6:36
up vote 2 down vote accepted

Blue pill can be a proof for this action. It can be used by malware and create malware which completely invisible to OS.

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Hmm.. didn't think of that one. +1. – Billy ONeal Jun 1 '11 at 4:55

I think it's because 90% of their customers expect a new PC to behave like their old one only faster. Turning on "Execute Disable", for example, can break legacy software so they don't enable it because the average Joe won't understand what's happened.

Turning on the TPM by default will cause Windows to load the drivers and prompt the user to set it up. Most people won't have a clue what it's about.

It's all about reducing support calls.

Those of us who do know and care about this stuff know enough to go into the settings and tweak them the way we prefer.

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Also, some options in the BIOS may not be available on certain systems anyway. My laptop has an option in the BIOS to enable or disable Intel Hardware Virtualization, but it's disabled by default. My CPU doesn't actually support it, so the option does nothing. – TuxRug Jun 1 '11 at 2:45
Andrew: xD does not break legacy software unless you flipped some crazy switches in the OS. Windows (at least) only uses xD in the OS itself by default. The user has to opt an application in to xD support, not the other way around. As for the TPM -- I agree with you. However, the TPM was enabled by default. (?!?!) – Billy ONeal Jun 1 '11 at 4:59
Nonsense. The NX/NXE flags apply to a CPU as a whole, and are not segregated by application. It is the operating system that does that, and it is of course necessary for an operating system to recognize and handle the processor exceptions raised when execution protection is turned on. If the operating system does not recognize this particular exception, as will be the case for operating systems written before the processor capability existed, the operating system will break if the processor capability is turned on, just as M. Cooper wrote. – JdeBP Jun 1 '11 at 9:31
@JdeBP: The operating system has to set the NX bit on a memory page in order for the NX bit to have any affect. That's certainly not CPU wide. NX is not a CPU wide specification, it's merely the x86's mechanism for enforcing execute permissions on a memory page. – Billy ONeal Jun 3 '11 at 6:05
The NXE flag, which I specifically named, is a per-CPU flag in a model-specific register (EFER). M. Cooper's point continues to stand. – JdeBP Jun 3 '11 at 9:28

My opinion is not specific in your case, as your workstation is actually very nice—I use one at the office too.

The other answers already give my main opinion, which is that I believe they do it to avoid wasting their Customer Service Support's time and therefore their profit margin. But I also believe certain manufacturers disable features to try and get you to purchase the more expensive computer, maybe under the Professional line, or the Extreme line, which may have features unlocked that appeal to the crowd they're selling it to in the same way the actual CPU and Motherboard manufacturers do.

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The thing is, all you have to do is flip a switch in the BIOS and you've got the feature. It's not a case of trying to get you to spend more money -- the hardware is capable of doing it. It's just disabled. These features don't make the system any faster, they just allow it to do more things (e.g. visualize 64 bit guests). – Billy ONeal Jun 1 '11 at 4:53
You're absolutely right, I think possibly I misread your question. I saw disabled as an option that could not be enabled by the user. What I'm talking about is that they disable something on a cheaper line of computers, knowing that that option is needed for most power users. Then they enable the option on their more expensive line, hoping that power users will opt for this more expensive line. – Paul Jun 3 '11 at 3:20

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