Microsoft has offered official confirmation that Windows Live OneCare is not on the list of security solutions compatible with pre-release development milestones of Windows 7. The Redmond company acknowledged that upgrading copies of Windows Vista running OneCare to Windows 7 Beta would produce an error message informing users that the security product failed to play nice with the next iteration of the Windows client. As a general rule of compatibility, Microsoft promised that software designed for Vista would also work with Windows 7. This is not the case when it comes down to Windows Live OneCare.

There are a variety of error messages that end users can come across according to the Redmond company. “These programs might not work properly after the upgrade. We recommend uninstalling these programs before upgrading. Cancel the upgrade, open Control Panel and search for uninstall a program.” This is the error message that end users are likely to come across during the upgrading process from Vista to Windows 7.

But at the same time, there are additional signals that the integration between OneCare and Windows 7 has not exactly gone as smoothly as possible. OneCare itself will inform users that “This program has known compatibility issues… Windows Live OneCare is incompatible with this version of Windows. For more information contact Microsoft,” when it first starts after a Windows 7 upgrade.

Users who ignore the incompatibility warning presented during the upgrade process and go ahead with the move to Windows 8 will come across the following error message after rebooting their computer: “The Windows Live OneCare service is not working or has been stopped. To correct this problem, try restarting your computer. If the problem continues, click below to get help.” When attempting to launch the Windows OneCare service, the error message presented will read as follows: “Windows could not start the Windows Live OneCare service on Local computer. Error 1150: The specified program requires a new version of Windows.”

Microsoft is advising users to completely uninstall Windows Live OneCare prior to upgrading to Windows 7. No word yet from the company whether it plans to introduce Windows 7 support, but such a scenario is highly unlikely, seeing as OneCare is a case of a “dead antivirus walking.” Back in November 2008, Microsoft announced that it was discontinuing OneCare as of mid-2009, and that it would introduce a free security offering, codenamed Morro in its place. The software giant revealed at the time that codename Morro would be tailored to Windows 7.

“Backups created with OneCare cannot be used with Windows 7. If you currently have data that only exists in a backup created using Windows Live OneCare, you should restore that data using Windows Live OneCare and then backup or copy that data to another location using Windows Backup or another backup utility,” the Redmond company added.