First it was Nvidia’s drivers with the fan control speed issues and now it’s McAfee and their XP killing update. It seems like a lot of company updates are hitting the fan.

The recent update of McAfee for their antivirus software on windows XP is causing computers to shut down and revert to an infinite loop of resets/restarts. The company has offered the following statement:

McAfee is aware that a number of customers have incurred a false positive error due to incorrect malware alerts on Wednesday, April 21. The problem occurs with the 5958 virus definition file (DAT) that was released on April 21 at 2.00 PM GMT+1 (6am Pacific Time).

Our initial investigation indicates that the error can result in moderate to significant performance issues on systems running Windows XP Service Pack 3.

The faulty update has been removed from McAfee download servers for corporate users, preventing any further impact on those customers. We are not aware of significant impact on consumer customers and believe we have effectively limited such occurrence.

McAfee teams are working with the highest priority to support impacted customers and plan to provide an update virus definition file shortly. McAfee apologizes for any inconvenience to our customers

So what exactly does McAfee’s 5958 virus definition do that it sends XP computers in an infinite loop of death? it seems that the 5958 DAT file flags svchost.exe file (a common Windows services file) as malware, deletes it and kills your machine.

How do I fix a computer that has updated to McAfee’s 5958 DAT file?

McAfee recommends the following solution

1. From a computer that has Internet access, locate and download the Recovery SuperDAT at http://download.nai.com/products/mcafee-avert/tools/SDAT5958_EM.exe and save it to portable media.
2. Take the portable media to each affected computer and run the tool.NOTE: If you are not able to run the tool on the affected computer, (re)start your computer in Safe Mode.
   For instructions on starting in Safe Mode, see http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx?mfr=true
3. Run the Recovery SuperDAT tool.
4. Restart in normal mode.

via here

The problem is that you still need a working computer to run download the file.  If you have none, ask a friend for this favor as it’s the only to recover your machine aside from a complete reinstall.  If you have any questions and/or clarifications, please post them in the comments.