Select the product you need help with
- Internet Explorer
- Windows Phone
- More products
Error message: "A script on this page is causing Internet Explorer to run slowly"
Article ID: 175500 - View products that this article applies to.
This article was previously published under Q175500
Because some scripts may take an excessive amount of time to run, Internet Explorer prompts the user to decide whether to continue running the slow script. Some tests and benchmarks may use scripts that take a long time to run. Therefore, you may want to increase the amount of time that passes before the message box appears. In Internet Explorer, the script time-out value can be changed on specific client computers by modifying a registry entry.
Sometimes, a webpage contains script that takes an unusually long time to run. If you are scripting an ActiveX control on a webpage to transfer a very large file or run a large database query, this often causes a significantly long delay. Internet Explorer 3.02 detects the long delay, and prompts the user with a dialog box that reads as follows:
The equivalent message box for Internet Explorer versions 4.0 through 8 reads as follows:
This page contains a script which is taking an unusually long time to finish. To end this script now, click Cancel.
This mechanism allows the user to stop misbehaved script that runs into an endless loop or otherwise is performing slowly.
A script on this page is causing Internet Explorer to run slowly. If it continues to run, your computer may become unresponsive. Do you want to abort the script?
In Internet Explorer 3.02, this message box can appear on machines running Windows 95. The version 3.02 browser is specifically looking to see if the script thread has pumped any windows messages in the last five seconds. There is no way to override this time-out period for Internet Explorer 3.02. If you are using an ActiveX control with long blocking operations, that ActiveX control should either employ an event mechanism and return control to the caller or call PeekMessage every five seconds to reset the time-out.
As of Internet Explorer 4.0 and later versions, the time-out is no longer a fixed value based on Windows messages. Internet Explorer now tracks the total number of executed script statements and resets the value each time that a new script execution is started, such as from a timeout or from an event handler, for the current page with the script engine. Internet Explorer displays a "long-running script" dialog box when that value is over a threshold amount. Internet Explorer doesn’t check on each instruction to see if it is over the limit. Periodically the script engine polls Internet Explorer with the number of statements executed and Internet Explorer checks if that is over the limit. Because of this mechanism, it is possible to execute more than the default limit without the dialog if the entire script execution finishes before the script engine polls Internet Explorer.
To have us change this time-out value in Internet Explorer versions 4.0 through 8 for you, go to the "Fix it for me" section. If you prefer to fix this problem yourself, go to the "Let me fix it myself" section.
Fix it for meTo fix this problem automatically, click the Fix it button or link, click Run in the File Download dialog box, and then follow the steps in the Fix it wizard.
Fix this problem
Microsoft Fix it 50403
Next, go to the "Did this fix the problem?" section.
Let me fix it myselfImportant This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/322756/ )How to back up and restore the registry in Windows
To change this time-out value in Internet Explorer versions 4.0 through 8, follow these steps:
Because the Internet Explorer versions 4.0 through 8 time-out is based on the number of script statements that are executed, the time-out dialog box does not display during ActiveX control or database-access delays. Endless loops in script will still be detected.
Did this fix the problem?
For more information about speed, security, and adaptability of Internet Explorer 8, visit the following Microsoft Web site: