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Windows Client for It Pros
Windows Server

AlbertMaberry

error code 0x87005b4

occurs when trying to open windows defender

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Answer

LeonRussell_977

The Windows Defender antispyware program that is part of the Vista operating system is disabled (to prevent conflicts) by various security programs including but not necessarily limited to AVG, McAfee, Microsoft Security Essentials and Norton.

The error message may occur because you are attempting to turn on Windows Defender after it has been turned off by the antivirus program you are using.

If using Microsoft Security Essentials see http://experts.windows.com/w/experts_wiki/89.aspx

Or check with the Support Forum of whatever antivirus program you are using.