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JSI Tip 6147. Internet Explorer on Windows XP issues 'Error 501/505: Not implemented or not supported'?

When you attempt to view a Web page, you receive an message similar to:

Error 501/505: Not implemented or not supported.

This error could be caused by 3rd party software interfering with Internet Explorer, or by the use of the HTTP 1.1 or newer protocol.

To workaround this issue:

01. Open Internet Explorer.

02. Use the Tools menu to press Internet Options.

03. Select the Advanced tab.

04. Clear the HTTP 1.1 box. 

05. Press Apply and OK.

06. If this settings change resolves the issue, exit this procedure.

07. Open Internet Explorer.

08. Use the Tools menu to press Internet Options.

09. Select the Advanced tab.

10. Clear the Show friendly HTTP error messages box.

11. Press Apply and OK.

12. When viewing the problem page, you should receive a more descriptive error message, similar to:

HTTP version not supported by <ProgramName>.

13. Either remove <ProgramName> to see if this resolves the problem, or contact the manufacturer about a fix.

NOTE: The HTTP 1.1 protocol is newer than HTTP 1.0. Some sites may still use HTTP 1.0, causing problems if you enable HTTP 1.1.

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