Can't resist adding so more info:
Customizing How Windows Handles Stop Errors
When Windows encounters a serious error that forces it to stop running, it takes the following actions:
The system displays a Stop message on the screen.
Based on the preferences defined for the current Windows installation, the system writes debugging information to the page file. When the computer restarts, this information is saved as a crash dump file, which can be used to debug the specific cause of an error.
Again based on the current preferences, the system either pauses with the Stop message on the screen or restarts when the crash dump information has been saved.
You can customize two crucial aspects of this process by defining the size of the crash dump files and specifying whether you want Windows to restart automatically after a Stop message appears.
By default, Windows XP automatically restarts after a Stop message. That’s the preferred strategy in response to a random, isolated Stop error. But if you’re experiencing chronic Stop errors, you may have more troubleshooting success by reconfiguring Windows to halt at the Stop message and wait for you to manually restart the system. To make this change, follow these steps:
Open the System Properties dialog box from Control Panel. (As a shortcut, click the Start button, right-click My Computer, and choose Properties.)
Click the Advanced tab and then click the Settings button under the Startup And Recovery heading.
In the Startup And Recovery dialog box, clear the Automatically Restart check box.
Click OK to make the change effective.
From the same dialog box, you can also define the settings for crash dump files. By default, Windows XP saves the smallest possible amount of information in a 64-KB file. After recovering from a Stop error, the system displays the dialog box shown. If you choose the Send Error Report option, the Small Memory Dump file is automatically sent to Microsoft.
tip - Clean up mini-dump files
--------------------------------------------------------------------------------
If you have a rash of Stop errors, mini-dump files can consume hard disk space unnecessarily. To clean the debris manually, open the %SystemRoot%\MiniDump folder and delete any files you find there. To automatically remove these files, use the Cleanup Manager options described in "Cleaning Up with Disk Cleanup."
In most cases, the information in a Small Memory Dump file is not sufficient to thoroughly debug an error. In the case of persistent Stop errors, a Microsoft support technician may ask you to create a more thorough crash dump file. To do so, open the Startup And Recovery dialog box using the steps outlined above, and change the selection in the Write Debugging Information list to one of the following options:
Kernel Memory Dump. This option includes memory allocated to kernel-mode drivers and programs, which are most likely to cause Stop errors. Because it does not include unallocated memory or memory allocated to user-mode programs, it will usually be smaller in size than the amount of RAM on your system. The exact size varies, but in general you can expect the file to be approximately one-third the size of installed physical RAM. The crash files are stored in %SystemRoot% using the file name Memory.dmp.
Complete Memory Dump. This option saves the entire contents of physical memory; as a result, it will be equal in size to your installed RAM. This can cause problems on systems with large amounts of RAM installed. On a system with 1024 MB of RAM installed, a crash dump file will use up 1 GB of disk space! The crash files are stored in %SystemRoot% using the file name Memory.dmp.
caution
--------------------------------------------------------------------------------
Change memory dump options only when requested to do so by a support engineer, and change the options back to their default settings after troubleshooting is complete.
When It’s Time to Ask for Outside Help . . .
The Online Crash Analysis feature, which is new in Windows XP, allows the operating system to send debugging information to Microsoft Product Support Services automatically after a serious error occurs. This action occurs only with your permission. You can do so anonymously or you can use your Microsoft Passport to send an acknowledged upload. In the latter case, a support technician may contact you to request more details. With luck, the technician can suggest a course of action that allows you to recover from the error. You can upload crash reports manually, using the Online Crash Analysis Web site. After uploading a crash report, you can check the status of your issue by returning to the site.