Why are local copies that use UNC names so slow?

A. Using Uniform Naming Convention (UNC) names (e.g., \) rather than native drive letters to copy files locally is about 10 percent slower. However, a larger slowdown in making local UNC copies (e.g., a copy that takes about 50 times as long as a copy that uses native drive letters) is the result of a bug in Norton AntiVirus (NAV) Autoprotect (including in NAV 2001, version 7). To work around this bug, you must stop the Autoprotect service from the Services applet in Control Panel and clear Autoprotect as an option from the NAV window. After you turn off Autoprotect, local UNC copies will behave normally.