Windows XP SP3 users reported that CA Antivirus falsely identified Windows XP system files and placing them in quarantine. Windows XP home office and small business users have reported the following files were affected.

c:\windows\system32\net.exe
c:\windows\system32\netsh.exe
c:\windows\system32\reg.exe
CA Internet Security Suite users should restore affected files from quarantine using the GUI. CA Threat Manager customers should search local hard drives for files with the extension .AVB and manually rename to their original file extension by removing the appended text on the original file name.
This is a false positive due to CA Anti-Virus Update # 6604 and has been corrected with CA Anti-Virus Update # 6606 or later.
Please update the CA Internet Security Suite software to avoid getting these alerts again.
Once the product updates are over you would need to restore quarantined items by following the article below:
View/ Delete/ Restore Files Quarantined by CA Anti-Virus