The nasty Sysprep Rearm 3-step limit and working around it.

If you haven’t heard of Rearm (or SkipRearm before) then this is a tricky little thing that Microsoft has introduced into Windows Vista and Windows 7, as part of the more complex activation thingys. And it is an annoying thing. Any one image can only be sysprepped three times before you get this thing kicking in and telling you that Sysprep had a fatal error with the Rearm component. I got this today when I took what was supposed to be my do-all, good-for-everything 64 bit 7 Enterprise image. Last week I copied it to a laptop, installed the laptop-specific stuff on it, then put it back onto the VM, and today I tried to sysprep it, and got this error.

The simple answer: don’t sysprep more than you have to. Keep a master image that hasn’t been sysprepped, and make all the changes you need to it. Then make a copy of it, and sysprep that copy. Whenever you need to make changes, go back to your master that hasn’t been sysprepped, make the changes on that, copy it, sysprep it, deploy it. It just means extra work copying files around.

I suspect this is the reason that MDT Sysprep stopped working the last time I tried to use it. The imager VM had the same image on it that it always had, and it had been sysprepped a few times. Enough to hit that limit. Even though I haven’t been able to find out what error was thrown, it would have been the same count as the sysprep I tried to do today, and so it failed.

As you may recall, one of the criticisms I had of MDT and AIK was the need to keep a 32 bit VM running to allow 32 bit installations to be serviced using these tools. Well, that won’t be an issue for much longer. I think we’re about to bite the bullet and go to 64 bit Windows on everything. And then the AIK and MDT can be installed on a 64 bit server and there won’t be any issue for them. What in fact I will do is install those on my server now and set up new 64-bit-only MDT/AIK shares that they service.

But for right now, for getting those laptops out, what I am going to do? Well after some thought I decided to start building my image again from scratch, this time making the necessary copies of the VHD so that it can be done properly this time. Another thing I did today is to run the Office 2010 OCT to make an installation that automatically puts the activation key in, so we don’t have to bother about the KMS to get things installed. So pretty soon I am going to be building a new image for our computer suite that is 64 bit and then they will all be changed over to 64 bit the next time they need reimaging.