Setting up a dedicated Vista boot option that uses /3GB


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I'm trying to set up a seperate boot option in the Vista bootloader that has /3GB turned on, which will leave my default boot option (standard Vista) untouched. I did this back in XP with ease (I miss boot.ini...) using two separate boot options (one that booted XP with /3GB and one without)and would like to replicate this functionality on my new Vista install. I only need /3GB for a handful of things, and don't want to mess with resetting it off or on all the time.

I've already cloned the Vista boot entry for my bootloader using EasyBCD; I just don't know how to go about setting /3GB on it for good. Does EasyBCD have this option? If not, how do I go about enabling it for that second boot option?

My bootloader currently looks like this:

-Windows Vista Ultimate <---this is the default one; don't want /3GB here

-Windows Vista Ultimate /3GB <---exactly the same as above (both booting from the same install), except I with to set this option to use /3GB

Any help would be appreciated.

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I'm trying to set up a seperate boot option in the Vista bootloader that has /3GB turned on, which will leave my default boot option (standard Vista) untouched. I did this back in XP with ease (I miss boot.ini...) using two separate boot options (one that booted XP with /3GB and one without)and would like to replicate this functionality on my new Vista install. I only need /3GB for a handful of things, and don't want to mess with resetting it off or on all the time.

I've already cloned the Vista boot entry for my bootloader using EasyBCD; I just don't know how to go about setting /3GB on it for good. Does EasyBCD have this option? If not, how do I go about enabling it for that second boot option?

My bootloader currently looks like this:

-Windows Vista Ultimate <---this is the default one; don't want /3GB here

-Windows Vista Ultimate /3GB <---exactly the same as above (both booting from the same install), except I with to set this option to use /3GB

Any help would be appreciated.

Not sure how to solve your problem. However, I came across this.

According to your signature, you 4GB of RAM, the above link is saying (if I read it properly) this will have no effect with 4GB systems.

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Not sure how to solve your problem. However, I came across this.

According to your signature, you 4GB of RAM, the above link is saying (if I read it properly) this will have no effect with 4GB systems.

I did see that too, but since it worked fine in XP, I'm assuming it'll work the same for Vista (giving the kernal just 1 GB and my applications the other 3). It doesn't hurt to try; if it doesn't work, deleting the extra boot entry wouldn't be difficult. :)

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Ah, I see. UserVA also worked in XP; it was used to fine-tune /3GB. What I meant by reading the article and still saying it ought to work was the mechanics (you'll notice it says No Change next to XP as well, though /3GB did its job wonderfully there), though I didn't realize they had rolled up the two into being one command (which I like).

So I suppose my question changes to this: If I boot into the boot option I'd like to dedicate to using UserVA, and run "BCDEDIT /Set IncreaseUserVa 3072" in BCDEdit, will that change stick, or will I have to re-do it each time I reboot into that second boot option? Also, will it leave my first boot option without UserVA enabled?

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I got it all working (so it seems). It does indeed look like its working. Here's the steps to do it (its pretty easy):

This is for Windows Vista *only*. Also note I did this with UAC in Silent Mode; you might get some UAC prompts while doing this if your UAC is still on and not running in Silent Mode. This shouldn't affect you other than having to click a few extra things. :p

Part I (Optional) - Create a New Boot Option for dedicated UserVA use

--------------------------------------------------------------------

1. Log in as an Administrator

2. Open the Start menu, type cmd in the Search box, and right-click on cmd.exe and choose "Run as Administrator"

3. Type in: bcdedit /copy {current} /d "Vista with 3GB" (Note: The "Vista with 3GB can be anything you wish; its simply the name that will display in the bootloader)

4. Hit enter; you should get a confirmation that it worked. Reboot to ensure the new option is there; if so, choose it.

Alternative Method: You can easily use EasyBCD to make a new boot option, and simply point it to the same partition as your existing Vista install.

Part II - Enabling UserVA (formerly known as /3GB)

-------------------------------------------------

1. Log in as an administrator using your newly created boot option (if you created one; if not, use your regular boot option. Note that if you only have one boot option in your bootloader, the bootloader is skipped entirely, so you can skip straight to logging in. Be sure you do so as an Administrator.).

2. Open the Start menu, type cmd in the Search box, and right-click on cmd.exe and choose "Run as Administrator"

3. Type in BCDEDIT /Set IncreaseUserVa 3072 (Note: the '3072' can be changed to suit your needs. I would not go below 2600 or higher than 3100 personally. Refer to Microsoft's guidelines on the /3GB & UserVA switches for XP for more information)

--This method will set the UserVA for the boot option currently in use. If you're following my mini-guide, this is what you want, and why I suggested creating a separate boot option so we could have a dedicated boot option for using UserVA.

--If you need to modify a different Vista boot option than the one you are currently using, use this instead: bcdedit /set {Your desired entry's SID} IncreaseUserVa 3072 (Note: replace 'Your desired entry's SID with the SID# for the boot option you wish to modify)

4. Hit Enter; you should get a confirmation message. Reboot. The next time you boot into the modified boot option, it should be using UserVA.

5. If you wish to check whether you did things correctly, simply type bcdedit in the command prompt. The modified boot option should have a userva option, whereas the other one(s) shouldn't. Example:

BCDEdit.jpg

Part III - Removing UserVA:

---------------------------

Frankly, the simplest and quickest way to do this if you're using a dedicated boot option for UserVA is to use EasyBCD to delete the UserVA-enabled boot option. However, if you wish to turn it off in the boot option you're currently using without removing that particular boot option (like if you didn't create a dedicated one), do this:

1. Open the Start menu, type in cmd in the Search bar, right-click on cmd.exe and choose "Run as Administrator"

2. At the command prompt, type this: bcdedit /deletevalue IncreaseUserVa (Note: This disables UserVA for the **current** boot option; make sure you are using the boot option that had userVA enabled before doing this).

3. Hit Enter; you should get a confirmation (this I cannot confirm, as I haven't disabled it yet). Reboot. Now UserVA will be disabled on that boot option. :D

I hope this helps. Others feel free to correct any mistakes I may have made. :)

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