My Windows XP computer is setup with 6 different users. Whenever I change between the users the computer reboots.

When Windows XP restarts without warning, this indicates there has been a serious system failure or error. However, instead of showing the error message the computer restarts when the error occurs. So, before we can figure out how to fix the error we need to determine which error is being thrown. To do this, we need to disable the automatic restart so we can view the error message. Go to the ‘Start’ menu > ‘Control Panel’ and open the ‘System’ control panel (you may need to click the ‘Performance and Maintenance’ category first). In the window that appears, click the ‘Advanced’ tab and under ‘Startup and Recovery’ click ‘Settings’. Under the ‘System failure’ heading, untick ‘Automatically restart’. Click OK then OK again. Restart the computer, and then try switching users and note the error message that appears. As the computer would have stopped with the error, you will need to manually restart the computer using either CTRL-ALT-DEL or manually powering-off (holding the power button on the computer for approximately 5 seconds).

You may also be able to find additional information on the error by looking in the Event Viewer. Take note of the time immediately before the error occurs, and then once the computer has restarted following the error go to the ‘Start’ menu > ‘Control Panel’ and open the ‘Administrative Tools’ control panel (you may need to click the ‘Performance and Maintenance’ category first). Open ‘Event Viewer’ and look under either the ‘Application’ or ‘System’ categories for any events which occurred at the date/time of the error. This may give you more insight into the problem.

Once you have obtained the exact error through either the error message or the Event Viewer, this gives us a better place to start in investigating the problem. Unfortunately, until I can see that error myself there is little I can suggest in the way of a solution. However, if you wish to forward me the error message I will research the problem further and hopefully find a resolution.

In the meantime, there are a few suggestions you can try. Firstly, as you have probably seen previously in this column, I commonly suggest for Windows XP problems you attempt to run the Windows XP System File Checker utility, in case any Windows system files are missing or have become corrupt. Go to the ‘Start’ menu > ‘Run’ and type ’sfc /scannow’ (without the quotes) and click OK. The SFC will begin operations. Once it has completed, it will exit silently with no user feedback.

Other users who experience a similar issue usually experience the problem when using Fast User Switching (i.e. click the ‘Switch User’ button). If the user logs-off completely, by clicking the ‘Log Off’ button, and then selects a new user at the Welcome screen the problem does not occur. So, if you are unable to resolve the issue with Fast User Switching, this may be an alternative method to switch users.