光驱的驱动旁边有黄色的叹号无法使用（错误代码 31）怎么办法
打开注册表，定位到：
| 代码如下 | |
| HKEY_LOCAL_MACHINE＼SYSTEM＼CurrentControlSet＼Control＼Class＼{4D36E965-E325-11CE-BFC1-08002BE10318}， | |
然后分别删除UpperFilters和LowerFilters两个字符串值。
然后关闭注册表，在硬件管理器中卸载原来的光驱驱动，然后再刷新。这个时候系统会提示找到新硬件并会正确安装光驱的驱动。
下面是国外网站的xp解决办法
Windows XP
1.Click Start, and then click Run.
2.In the Open box, type regedit, and then click OK.
3.In the navigation pane, locate and then click the following registry subkey:
| 代码如下 | |
| HKEY_LOCAL_MACHINE＼SYSTEM＼CurrentControlSet＼Control＼Class＼{4D36E965-E325-11CE-BFC1-08002BE10318} | |
4.In the right pane, click UpperFilters.
Note You may also see an UpperFilters.bak registry entry. You do not have to remove that entry. Click UpperFilters only. If you do not see the UpperFilters registry entry, you still might have to remove the LowerFilters registry entry. To do this, go to step 7.
5.On the Edit menu, click Delete.
6.When you are prompted to confirm the deletion, click Yes.
7.In the right pane, click LowerFilters.
Note If you do not see the LowerFilters registry entry, unfortunately this content cannot help you any further. Go to the "Next Steps" section for information about how you can find more solutions or more help on the Microsoft Web site.
8.On the Edit menu, click Delete.
9.When you are prompted to confirm the deletion, click Yes.
10.Exit Registry Editor.
11.Restart the computer.
