Since Microsoft will not provide a direct upgrade path from Beta to RTM, early adopters already testing Windows 7 Service Pack 1 will need to download the first public development milestone of the upgrade. At the same time, since Windows 7 SP1 is in Beta stage, the service pack could introduce various problems on a machine, specifically issues that weren’t there when users were running the RTM flavor of the operating system. In such cases, and in others, customers might need to uninstall Windows 7 SP1 Beta.

One thing to keep in mind is that when installing the service pack, backup files are created in order to ensure that removal will be possible. In this regard, customers should steer clear of the Disk Cleanup Wizard, which will erase the backup files, making the uninstall process impossible. More »

Just as it was the case for Windows Vista, Microsoft’s latest iteration of the Windows client can also be uninstalled, although “uninstall” does not specifically describe the process that end users will need to take in order to revert to a previously existing copy of a Windows OS. At the same time, also as for its predecessor, Windows 7 can only be removed and the previous Windows platform reinstated in a single installation scenario. Namely, uninstalling the latest version of the operating system is only possible if users installed Windows 7 as a new installation over an earlier version of Windows in the first place.

Obviously, clean installs of Windows 7, where no old OS existed on the hard drive, cannot be uninstalled. The same is valid for users that opted to upgrade from Windows Vista to Windows 7, as well as for those who created multi-boot configurations, deploying Windows 7 alongside older Windows releases.

Uninstalling Windows 7 is only possible if “You used the Windows 7 installation media to install Windows 7 to the same hard disk drive on which you had Windows XP, Windows Vista, or another version of Windows 7 installed. In this scenario, the Windows 7 installation will have created a Windows.old folder that contains your previous operating system and personal files. This Windows.old folder is in the root of the Windows partition,” Microsoft noted.
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To uninstall Windows 7, you must determine your specific installation scenario from the scenarios that are listed in this section, and then follow the steps for that scenario.

Scenario 1: You installed Windows 7 on a Windows-based computer

You installed a version of Windows 7 as a new installation over Windows XP, Windows Vista, or another version of Windows 7. You used the Windows 7 installation media to install Windows 7 to the same hard disk drive as the original operating system.

In this scenario, the Windows 7 installation will have created a Windows.old folder that contains your previous operating system and personal files. This Windows.old folder is in the root of the Windows partition. To revert to this previous operating system, click the following article number to view the article in the Microsoft Knowledge Base:

971760 How to restore a Windows 7-based computer to a previous Windows installation by using the Windows.old folder.
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