今天卸载Intervedio WinDVD后，突然发现DVD光驱在系统中找不到了。Device manager中Device status是：

Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39) 

开始试图更新光驱驱动程序，总是说系统已经安装最新的驱动（这是事实，因为改动没有破坏光驱驱动）。那么说应该是驱动上层的系统的问题了。到MS论坛上一看有N多的人遇到类似的问题，详见：

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=857993&SiteID=1

其中有高手提供了解决办法：

http://support.microsoft.com/kb/314060

原来可以通过修改注册表来解决。试了用手动修改注册表的方法2，简单有效

Step 1: Start Registry Editor

Click  Start , click  Run , type  regedit , and then click  OK . Registry Editor starts.

Step 2: Delete the UpperFilters registry entry

1.	In Registry Editor, expand My Computer, and then expand HKEY_LOCAL_MACHINE.
2.	Expand SYSTEM, and then expand CurrentControlSet.
3.	Expand Control, and then expand Class.
4.	Under Class, click {4D36E965-E325-11CE-BFC1-08002BE10318}.
5.	In the right pane (topic area), click UpperFilters. Note An UpperFilters.bak registry entry may also appear. To delete the UpperFilters registry entry, you must click UpperFilters and not UpperFilters.bak.
6.	On the Edit menu, click Delete.
7.	When you receive the following message, click Yes to confirm the deletion of the UpperFilters registry entry: Are you sure you want to delete this value?

The UpperFilters registry entry is removed from the {4D36E965-E325-11CE-BFC1-08002BE10318} registry subkey.

Note  Do not exit Registry Editor. You must have this program for the next step.

Step 3: Delete the LowerFilters registry entry

1.	In Registry Editor, expand My Computer, and then expand HKEY_LOCAL_MACHINE.
2.	Expand SYSTEM, and then expand CurrentControlSet.
3.	Expand Control, and then expand Class.
4.	Under Class, click {4D36E965-E325-11CE-BFC1-08002BE10318}.
5.	In the right pane (topic area), click LowerFilters. Note An LowerFilters.bak registry entry may also appear. To delete the LowerFilters registry entry, you must click LowerFilters and not LowerFilters.bak.
6.	On the Edit menu, click Delete.
7.	When you receive the following message, click Yes to confirm the deletion of the LowerFilters registry entry: Are you sure you want to delete this value?The LowerFilters registry entry is removed from the {4D36E965-E325-11CE-BFC1-08002BE10318} registry subkey.
8.	Exit Registry Editor.

Step 4: Restart the computer

If a CD recording program no longer works after you restart the computer, you must reinstall the CD recording program.