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Windows deployment preflight checks – Part 1: Introduction

Before you deploy a new Windows image, you should always perform a few preflight checks. This article gives an overview of the topic. In the next article, I discuss a script that helps you with this task.

What are preflight checks?

When you start a Windows deployment, once you are happy with the image it’s time to deploy it. However, there are quite a few obstacles to overcome that can stop your deployment at the first hurdle. For instance, what if the target disk is encrypted? Deployments only work with NTFS owing to the use of WinPE, so deployment will fail unless you format the disk. There is a whole list of prerequisites to think about. The main areas to address before deploying an OS to a machine are listed in Table 1 – Requirements overview.

Check	Action/task	Expected result
1	Hardware verification	Hardware meets minimum specification
2	OS verification	OS is valid
3	Domain verify	Meets authorized domain

Table 1 – Requirements overview

Check 2 is a good example of avoiding disaster. If you were using SCCM and someone clicked the wrong button and advertised your XP deployment to all machines, including servers, check 2 suddenly becomes a lifesaver.

Check 1, hardware verification, covers the biggest list of potential obstacles. A sample list of hardware checks you can make is shown in Table 2 – Detailed hardware requirement checks.

Check	What to check	Why to check	Avoids this risk
1	Vendor (make)	Limit the deployment to machines the organization supports	Building a visitor/guest laptop
2	Model (is in list)	Limit deployment to known hardware models	Building unsupported hardware
3	RAM greater than x	Some OS versions won’t install	Deployment abort if machine is not up to specifications
4	Disk type (HDD is not RAW)	Disk has to be NTFS	Deployment abort if disk is encrypted or is in bespoke OEM format
4a	Disk free space	Target disk has free space	Data migration failure later
4b	Disk total size	Target disk is big enough for new OS	Deployment failure
4c	Disk SMART health	Establish target disk is reliable	Target disk failure
5	CPU architecture	Confirms whether CPU is 32- or 64-bit	Building 64-bit onto 32-bit machines
5a	Prefer disk in SATA mode	BIOS may be set to legacy mode	Running Windows on legacy
5b	Prefer BIOS boot HDD first!	Media builds need to boot off HDD	Deployment looping
6	Boot count (MDT)	Target may have multiple boot	Overwriting the wrong drive
7	AC power (not battery)	Laptops need PSU	Shutting down of laptop while deploying if battery fails
8	Network	Network connect	Building over wireless (not a good idea)

Table 2 – Detailed hardware requirement checks

With MDT 2012, Microsoft has introduced the User Driven Interface (UDI) wizard that attempts to prepare machines for deployment running checks. Underneath the new wizard are some VBScripts that check various requirements. Unfortunately, UDI only supports Windows 7 (not XP). So I’ve written my own XP UDI script. The next article shares the script and its design. See this script in action in Figure 1 – Custom UDI for XP deployments.

Custom UDI for XP deployments