Monday, April 19, 2010

Can you set DEP to "AlwaysOff" on your Dell laptop?

It seems that many people cannot - and unfortunately, this post does not talk about a solution, but rather as a heads-up, or a possible point of focus, for people who might have a solution to offer.

But what is the problem?

Well, as far as I understand it (disclaimer: I do *not* own a Dell laptop), Dell laptops come with a version of preinstalled Windows Vista or Windows 7 on them which has some funky partition mapping on the drive, as well as some disabled features.

For various reasons, there comes a time when users will want to turn the Data Execution Prevention feature off, by opening a Command Prompt Window and entering "bcdedit /set nx AlwaysOff". (This helps run applications that were developed before Vista was available which otherwise trip the DEP flags and crash on the user - some of them being Microsoft's own Flight Simulator series, FS2004 and FSX).

The command can be successfully executed (with administrator rights or elevated privileges), but when the user reboots (sometimes MUCH later on), they are faced with an error 0x7b and a Blue Screen of death (BSOD).

So far, the ONLY reports we have are coming from users with Dell laptops who have NOT scrapped the Dell-provided Windows installations.

The obvious workaround is for these users to FORMAT their drives and install a clean NEW version of Windows (preferably, Windows 7 x64 now), that does NOT come from the Dell-provided disks.

All attempts at contacting Dell about this problem have been met with no success for the moment.

So... do YOU have a solution for this problem? If so, and you are STILL running your Dell laptop with the original, Dell-installed Windows and you were able to turn DEP AlwaysOff, I'm prepared to offer you a free Concorde-X license as a thank-you for sharing that information with me :).


Daniel said...

Hi, my name is Daniel, I'm a current microsoft employee, and I can tell you is that DEP Cannot be fully shut off forever as the computer reboots it will restart. But You can make windows bypass DEP for every program here are the steps(for vista and 7):

-Right Click on Computer and then click Properties

-Then click Advanced System Settings

-Click on the Advanced tab then click on Settings on the Performance box

-Go to tab Data Execution Prevention

-Click on the second dot where says "Turn on DEP for all programs and services except those I select

-Now click on add, then add the FS9.exe and FSX.exe in there

Now it should all be great.

Lefteris said...


I don't know what area you're working for at Microsoft, but the 'bcdedit' call does exactly that: resets DEP to off, every time the machine reboots.

Now, with Dell PCs, that's a different story...

Anonymous said...
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Anonymous said...

Lefteris: not that I have a fix but I was under the impression with Vista at least that it can't be turned off. You can supposedly turn it off for applications, but as far as Microsoft's OS code is concerned it's always on as opposed to XP which has that option. The fix unfortunately is Win7 which seems to have revised code for DEP.

Lefteris said...

That's not true. Vista and Win7 share the same command to turn DEP off. The problem lies entirely within the Dell BIOS which has some code which croaks when DEP is disabled...

frantico said...

I've an Inspiron 1545 and experienced the same issue.

Disabling DEP on x86 Windows cause the operating system to fail.

This problem doesn't occur with x64 and IA64 systems.

However, there's a workaround to prevent x86-based OSes to BSOD intermittently after disabling DEP, though I'm not as 100% certain if it works.