held down until Windows checks for it, it may be a considerable amount of time before it becomes effective. The time taken primarily depends on the time to recognise the new hardware and the time taken for CD-ROMs to spin up. It is unsafe to rely on this method. Auto Insert Notification Certain Media Change Notification events may be suppressed by altering certain Registry entries. "Media Change Notification" is the generic term; for CD-ROM drives, the specific term is "Auto Insert Notification". For CD-ROM drives, changing the value of this Registry entry to 0 will disable Auto Insert Notification for CD-ROM drives only. A Windows restart will be necessary. Under Windows 95/98/ME, this setting can be changed under Device Manager, accessible from the System icon in Control Panel. Although the Registry entry is named "AutoRun", it only suppresses the MCN message. The MCN message does trigger AutoRun initiation but it also instructs the Explorer shell to update its views and contents. Thus, as a side effect only, this disables AutoRun for CD-ROM drives. However, Explorer will now not update its view when a new CD is inserted; it will show the contents of the previous CD until is pressed or View/Refresh is selected from the Explorer menu. This could result in severe confusion for users. For this reason the Media Change Notification message should not be disabled unless there is absolutely no alternative; AutoRun can be disabled for individual drives using Group Policy or the Registry. This entry is used to suppress the MCN message for specifically listed type of CD-ROM drive, primarily CD-ROM changers. The data is a set of device identifiers, which matches those identifiers reported to the system by the devices themselves. The default value for this entry consists of products identified by Microsoft testing as being unable to support AutoRun. This entry should not be altered from its default. Editing Group Policy AutoRun may be suppressed on particular drives and drive types by using the methods described in the Group Policy section. However, the Group Policy Editor is not available on Home versions of Windows XP and does not provide any fine-grained drive selection facilities. However, Group Policy would be the accepted method of disabling AutoRun on an entire Windows domain. Registry files A Registry setting file can be created that, when executed, makes the desired changes in the Registry. In the above example, AutoRun would