Microsoft issued a hotfix for Windows XP Service Pack 3 last week that it says "could resolve" a Windows registry corruption problem associated with third-party security software. The problem was first discovered just over a month ago, and it notably affected users of Symantec's Norton Antivirus suite of products.
Some users who installed XP SP3 reported seeing garbled system entries that cluttered the Windows registry. The corruption in the registry led to problems such as lost Internet and wireless connections, along with uninitiated restarts caused by sporadic registry subkeys.
Microsoft provided an explanation for the problem in a Knowledgebase posting on Friday. The issue "occurs when the Fixccs.exe process is called during the Windows XP SP3 installation," the KB article explains. "This process creates some intermediate registry subkeys, and it later deletes these subkeys. In some cases, some antivirus applications may not let the Fixccs.exe process delete these intermediate registry subkeys." When the problem occurs, "certain applications" within Windows, such as "Device Manager and Network Connections" may be unable to function, Redmond added.
this one exactly came from MSFN