Windows 2008/R2 & SysPrep - Still Necessary

Most people are virtualizing these days. One of the great things about virtualization is that you can create a VHD of your guest and clone it for very fast build outs. But, despite what Microsoft has been coming out and saying, you STILL need to SysPrep your machine AND make sure to check the 'generalize' option before making a clone of your .VHD. (I recently made the mistake of not checking the 'generalize' option when doing SysPrep, and it essentially made it pointless.) If you don't, and especially if you create a domain controller from this image, you will have all kinds of weird things happen to you without it throwing any errors. Things such as not being able to add domain accounts to local user groups (it will show a weird SID name'd version of the account/group, and it will then disappear when clicking ok or apply) as well as failure for authentication, etc. It will drive you up the wall, so be careful!

Here are the instructions for SysPrep;

1) Run Sysprep (on Windows Server 2008 this is located in c:\Windows\System32\Sysprep\Sysprep.exe)
2) Ensure ‘System Out-of-Box Experience (OOBE)’ is selected
3) Tick the ‘Generalize’ option (this resets the SID)
4) Select ‘Shutdown’ from the Shutdown Options.
5) Once the machine has shutdown, take your image and you are good to go!