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If this article does not describe the error message that you are receiving, view the following Microsoft Knowledge Base article to view more articles that describe error messages:
315854 Windows 98 and Windows Me error message resource center
When you try to open Control Panel, you may receive one of the following error messages, and Microsoft Windows Millennium Edition (Me) may quit unexpectedly:
Explorer has caused an error in unknown.
Explorer has caused an error in Kernel32.dll.
Explorer has caused an error in file name.cpl.
NOTE: To more effectively search the Microsoft Knowledge Base, use keywords that relate to your issue. If you are searching for troubleshooting information that is not mentioned in this article, search the Microsoft Knowledge Base again by using keywords that are listed in the following Microsoft Knowledge Base article:
242450 How to Query the Microsoft Knowledge Base Using Keywords
This issue can occur if the Windows\System folder contains a Control Panel file (.cpl) that is damaged or incompatible with Windows Me. For example, if the Windows\System folder contains certain versionsof the Mca.cpl file that is included with earlier versions of the MotorolaSM56 modem software.
To resolve this issue:
Start your computer in Safe mode. Restart your computer, press and hold down CTRL after your computer completes the power-on selftest (POST), and then on the Startup menu, click Safe Mode.
Click Start, point to Search, and then click For Files or Folders.
In the Search for files or folders named box, type:
Click Search Now.
IMPORTANT: Before you rename files as part of this step, make a list of the original file names for tracking purposes.
In the Search Results pane, right-click a .cpl file in the Windows\System folder, and then click Rename.
NOTE: Rename the Mca.cpl file first (if it exists).
Rename the first file in the Search Results pane to an .old file extension. For example, if the file name is Example.cpl, rename the file to Example.old. Also, note which file you have renamed on the list you made in step 5.
To determine if you have renamed the damaged or incompatible .cpl file, try to open Control Panel. Repeat steps 5 through 7 until you are able to open Control Panel. When you can open Control Panel, verify that the last file you renamed is the damaged or incompatible file, and then continue to the next step.
Rename all of the files you renamed in step 7 back to the original file names, except for the file that you determined is causing the issue.
Restart your computer.
If the .cpl file that causes the issue is a file that is included with Windows Me, you must extract a new copy of the damaged .cpl file to the Windows\System folder. To determine if the .cpl file that causes the issue is a file that is included with Windows Me, view the list of .pl files in the More Information section of this article.For more information about how to extract a file in Windows Me, click the following article number to view the article in the Microsoft Knowledge Base:
265371 How to extract and replace a protected file in Windows Me
NOTE: If the .cpl file that causes the issue is not a file that is included with Windows Me, it may be a file that is included with a third-party program. If the file is included with a third-party program, contact the manufacturer of your program to determine how to resolve this issue. If the issue is resolved by renaming the Mca.cpl file, you may want to download updated drivers for your SM56 modem from the following Motorola Web site:
Later versions of the SM56 modem software provide a tool (the Sm56hlpr.exe tool) on the right side of the taskbar, instead of the Control Panel tool (the Mca.cpl tool).As of October, 2000, Motorola does not include the Mca.cpl file with any of their modem drivers, and this file is not available to download on the Motorola Web site. When you install the latest drivers for the SM56 modem, the Mca.cpl file from your Windows\System folder is not removed.
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.
Windows Me Control Panel (.cpl) files are protected files that are stored in the Windows\System folder. Some other programs or tools may add .cpl files to the Windows\System folder to provide custom features or settings for the program or tool. The following list contains the standard .cpl files that are included with Windows Me: