IT Expert Voice

Though Windows 7 is still pretty much a newcomer to the desktop operating system scene, it’s been around long enough that IT pros will encounter the occasional circumstance that demands — or at least calls out loudly for — a complete reinstall of this much-touted OS. In the sections that follow, I lead you through some cases where a reinstall is highly recommended (if not absolutely required) to make a PC work properly.

Windows 7 has been around in full commercial use for several months, depending on how you count: since August 2009 (MSDN release) or October 2009 (commercial release). Though it may seem that reinstalling Windows is unnecessary, in some cases such a maneuver makes good sense. These include a switch from 32- to 64-bit environments, changing your BIOS hard disk access mode, and for classic Windows degunking maneuvers.

Making the 32- to 64-bit Switch

The decision to switch from some 32-bit Windows 7 version to an equivalent 64-bit version absolutely, positively means that you must perform a custom install on your target PC. The 32-bit version is called x86 in Microsoft parlance and included in ISO filenames such as en_windows_7_professional_x86_dvd_x15-65804.iso, but the 64-bit version is called x64 as in en_windows_7_professional_x64_dvd_x15-65805.iso. There is no upgrade path from 32- to 64-bit Windows, so making this switch involves blowing away the old install and replacing it with an entirely new one.

If you find yourself facing this switchover, here’s a list of handy tools and activities you should undertake before actually firing up a Windows 7 reinstall:

1. Use the Windows 7 Upgrade Advisor’s 64-bit report to look for potential driver or software incompatibility issues. Fix anything that might appear herein, and you’re more or less guaranteed a smooth install when the time comes.


Figure 1: The Windows 7 Upgrade Advisor proffers a detailed 64-bit report when its analysis completes.

2. Download and use the Windows 7 USB/DVD Download Tool for your reinstall. This free, nifty download from the Microsoft Store lets you turn a 2GB or bigger USB Flash drive (UFD in Microsoft-speak) into a bootable installer for your chosen Windows 7 ISO file. It’s not only much faster than a DVD (which this program will also burn for you, if you like) it’s also much handier if and when you need a bootable Windows 7 repair toolkit as well.
3. Make two complete backups of your 32-bit environment before you fire off the installer: one image backup and one conventional backup. You can use the Windows 7 Backup and Restore utility for these purposes, or a third-party product of your choosing. (I like Acronis True Image Home because it lets me restore an image to the drive of my choosing, whereas the built-in Windows software only writes to the system drive on the target machine.)

With these items at hand or completed, you can blow away a 32-bit system secure in the knowledge that you can get back to that system by restoring one of your backups, if something unexpected pops up and prevents you from achieving a successful 64-bit Windows 7 install instead.

Switching SATA Drives from IDE Emulation to AHCI or RAID Mode

Those PC systems that include an Intel I/O controller hub (ICH5, ICH6, …, ICH10) to which an SSD is added after Windows 7 is already installed (probably as a system drive), or whose users simply want to squeeze the best performance possible from their SATA drives, may wish to switch their BIOS settings from IDE emulation to support AHCI (the Advanced Host Controller Interface) or RAID (Redundant Array of Inexpensive Disks). These settings permit PCs to exploit advanced SATA features that include native command queuing (NCQ) plus hot plug or power management for hard drives.

Here’s what Intel has to say about turning these features on in a PC’s BIOS:

Figure 2: You might want to read the whole Intel Raid Storage Technology (Intel RST) file.

I don’t know how seriously readers may be inclined to take such a warning from Intel, but to me the prospect of an unbootable system is not terribly encouraging. That said, I have tried other methods to switch from IDE emulation to AHCI or RAID mode on a system with Windows 7 already installed, and I have never experienced this kind of crash myself on ICH9 or ICH10 based systems (but you need to go into “Dirty Harry mode” and ask yourself if you’re feeling lucky today before you try this maneuver). Whether you jump straight into a reinstall at Intel’s urging or try the workaround, be sure to make the requisite dual backups so you can rebuild the system from “bare metal” should circumstances make that necessary.

The workaround basically consists of finding and copying the necessary iastor.sys driver file into C:\Windows\System32 (for x86 Windows 7 systems) or C:\Windows\System32\DRIVERS (for x64 Windows 7 systems). You can search the Intel site for the latest chipset drivers and downloads pretty easily to locate the necessary files. (You can usually find F6 standalone download files for use during Windows installation, which works equally well post installation for those willing to shoulder the related risks.)

The Ultimate Windows 7 Degunking Technique?

With my hat off and my fervent thanks to Jeff Duntemann, inventor of this term and co-author (with Joli Ballew) of the excellent book Degunking Windows, 2e, I submit that those who install and uninstall lots of software on their PCs, or whose machines go through lots of change and ferment, may decide from time to time that blowing away the current Windows install and restarting afresh is the right thing to do.

On my heavily used-and-abused test machines, in fact, that happens at least once every six months, if not more frequently than that. The book lists reinstalling Windows as one of its “Last Resort Degunking Techniques,” but in fact if you don’t have too many applications to reinstall after reinstalling the OS and all its many updates and patches, this can actually go faster than serial application of all the other, more detailed and focused degunking techniques instead (file cleanup, desktop cleanup, drive defragmentation, removal of unused or unwanted applications, and so on and so forth).

If you find yourself dealing with ever-slower bootup and shutdown, lengthy pauses when accessing the file system, slow application launches, and other signs of lagging performance, some kind of degunking is usually called for. Being something of a “cut to the chase” guy myself, I’ve learned that a clean reinstall is often the best and fastest path to a better behaved Windows desktop, for as many Windows versions back as I can remember (3.0 or 3.1, if memory serves). As a last resort technique, it will probably also work for your users, too — especially those who are allowed to install programs or browser add-ons of their choosing.

If You’re Going to Reinstall, Please Do It Right

Just remember my earlier advice in the story. Get your tools together, and go ahead and build yourself a bootable UFD with the Windows 7 ISO file of your choosing (3-4 GB is needed for x64, and 2-3 GB for x86 versions, if my adventures with Windows 7 Starter, Professional, and Ultimate can be a guide). Make sure you’ve got a readable file-by-file backup of your original install (in case you need to go back and grab something later) as well as an image backup (in case you want to restore the drive to its original condition later), and you’ll be good to go. Have fun, but stay safe!

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