Article ID: 324760 - View products that this article applies to.
When you try to use your modem on a Windows XP-based computer, you may receive an error message similar to the following:
Error 633 Modem is already in use.
This behavior may occur when another device with a driver that is incompatible with Windows XP is in conflict with the modem. For example, this problem can occur with outdated Palm Pilot software.
To resolve this issue, follow these steps:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
For additional information about Palm Pilot software and Windows XP, click the article number below to view the article in the Microsoft Knowledge Base:
308368For additional information about troubleshooting modem problems, click the article number below to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/308368/EN-US/ )Windows XP Upgrade Advisor Warning About the IrDA Protocol
308022The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.
(https://support.microsoft.com/kb/308022/EN-US/ )Resources for Troubleshooting Modem Problems in Windows XP
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.
Article ID: 324760 - Last Review: July 31, 2014 - Revision: 3.0