If you haven't rolled out Windows XP yet because you're concerned about compatibility issues with your organization's proprietary applications, you'll definitely want to check out the Application Compatibility Toolkit.

You can find it on the Windows XP Professional CD in the /Support/Tools folder. To install it, just run the Act20.exe file.

While Microsoft designed this toolkit primarily for application developers, it provides a lot of information that you can use for troubleshooting and investigating application compatibility issues. A particularly useful part of the Application Compatibility Toolkit is the Application Verifier (AppVerifier) tool, which allows you to configure a comprehensive series of tests to run in the background so you can monitor your applications' interactions with the Windows XP operating system.

The AppVerifier tool features a very user-friendly interface that makes it easy for you to test applications. Follow these steps:

1. Open the AppVerifier tool by going to Start | Programs | Application Compatibility Toolkit | AppVerifier.

2. Click the Add button.

3. In the Add Application dialog box, select the application you want to test, and click OK.

4. In the Test Settings section, select which tests you want to perform, and click the Run button.

5. Use the selected application as you normally would.

At any point in time, you can investigate the log file by switching back to the AppVerifier tool and clicking the View Logs button. You can also export the log file for later analysis.