What exactly does sysprep do and when should it be used? I deploy many VMs and VDIs by cloning other VMs or deploying from templates. I am working on updating the base images and have done all other changes needing to be done. Now that I'm ready to start deploying from them I'm wondering if it's advisable to sysprep and if I need to do it on each deployment or only once on the base image? I've had some people tell me that sysprep should not be run on virtual machines.

I'm using vSphere Client version 5 and am mainly dealing with Windows 7 and Windows Server 2008 R2.

Here's one more question. If sysprep only needs to be done on the base image how come everyone's up in arms that there's a limited number of times sysprep can be done on a copy of Windows 7?

Aside from the SID what does sysprep change?

  • window update id .... that name wsusid or "W"indow "su"ck"s" ID.
    – user218473
    Jul 30, 2013 at 13:13
  • assume your template have sysprep once, every image you clone have at strike 1, sysprep it again became strike 2. So there would not be problem to sysprep every clone image, which set all of them to strike 2. The biggest problem is that your settings are wiped after sysprep.
    – user218473
    Jul 30, 2013 at 13:24
  • secedit /export and secedit /import would be a solution without domain. Go group policy + init scripts if there is domain, which is the most straight forward methods.
    – user218473
    Jul 30, 2013 at 13:27

3 Answers 3


Sysprep should be run on the base image (reference machine) prior to capturing the image.

The TechNet article 'How Sysprep Works' is for Windows 7.

Since you say you are new at this, I'll leave you with some links that should help.

Basic Deployment information:

Step-by-Step: Basic Windows Deployment for IT Professionals

Windows 7 Deployment Frequently Asked Questions

Something to consider while creating reference images:

Desktop Image Management: Build a Better Desktop Image

Last, the Deploy Windows 7 page of the Springboard Series on TechNet has many more articles and videos to help deploy Windows.

Hope this helps,

  • "Sysprep should be run on the base image (reference machine) prior to capturing the image" I don't quit follow. What do you mean capture the image? You imply we already have the base image so what would we be capturing?
    – Celeritas
    Jul 18, 2013 at 3:05
  • @Celeritas I mean, in the process of creating a base image, you would setup the reference machine the way you want it, then run sysprep (usually with the /generalize and /oobe options) then capture the image. This becomes the base image. There is no need to sysprep after deploying (which is what I think you are asking). The video that you linked, he is running sysprep on his reference machine and after shutdown is when he would capture the image (his new base image).
    – dwolters
    Jul 18, 2013 at 14:39
  • ya that was what I was asking. Unfortunately I don't think I have a reference machine. I'm starting from "a base image" that was done poorly and upgrading it. I take it the terms reference machine and base image are somewhat subjective.
    – Celeritas
    Jul 18, 2013 at 16:40
  • 1
    @Celeritas Yes, I assume you are deploying the base image (to a VM or real hardware), updating it (now it's the reference machine), then running sysprep and re-capturing the image (new base image). The term 'base image' is a bit vague, but in this case, I mean it to be the finalized image that you are going to deploy.
    – dwolters
    Jul 18, 2013 at 17:04

The reason you want to sysprep is because Microsoft need you run it. You will run into problems such as window updates and etc, because Microsoft have put some unique id on the machine when it activates and something else.

And if you clone them, those unique id will got double and many Microsoft system management program such as Window Update server, Window online updates will consider 2 machine are the same and run into problems.

While peoples suggest that MS leave it intentionally since it helps them to make sure you activate every machine and let them count correct no of license you have installed.

Just more note, Microsoft partners (Sym*****, etc) have do them a favor to keep this behavior as well.

So, what you need to do is to run sysprep and then activate it once you clone it. And you got many of your users & machines settings wiped and start a new.

Alternatively, found alternative solution to do window and antivirus updates.


The answer by WinOutreach4 is very thorough for physical PCs/Servers, but when dealing with VMWare and Templates, I agree with those who have told you not to Sysprep. Convert the Template to a VM, Update it then Convert it to back to a Template. Nothing Else. When you deploy from the Template, customize the image and check the box to generate new SIDs, this is all you need.

The way I understand Sysprep is to generalize and/or repackage a windows install so you can remove unused drivers. It is absolutely a must when doing a P2V (Physical to Virtual) or creating an image which you will install on multiple types of PC hardware.

If you want to create an unattend.xml Sysprep an image once, that is a good way to automates much of the basic setup and I strongly encourage you to look into the WAIK Windows Automated Install Kit for help making your XML file.


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