updated 04:40 pm EST, Mon November 30, 2009
Windows fix conflicts with security apps
A Microsoft security fix has inadvertently left some Windows PCs almost inoperable, app developer Prevx warned this weekend. Those running some security apps after applying a November 10th fix have reported the system starting up with a black screen, nicknamed the "black screen of death," that shows only a single Explorer window. It doesn't prevent complete use of the system but bars use of the Start menu and other features on Windows XP, Vista and 7 systems.
Prevx has developed a fix for affected computers and says the issue likely stems from changes to the Access Control List, which governs the exact permissions each app has on a system. Certain apps don't recognize the changes and as a result conflict with Windows.
Microsoft will be contacted with details about the issue, but as of Monday the developer hasn't provided a patch.
The flaw is a minor embarrassment for Microsoft, whose Windows 7 is just over a month old and is entering the critical holiday period. Many pre-assembled Windows PCs today often come with trial versions of security software already installed and may encounter the conflict depending on the program they use.