Hola, supuestamente según MS el código debería ser
7000 para IE7.
Saludos
Nicolas Perichon
info de Microsoft:
msdn.microsoft.com/en-us/library/ee330730%28VS.85%29.aspx#browser_emulation
10001 (0x2711)Internet Explorer 10. Webpages are displayed in IE10 Standards mode, regardless of the !DOCTYPE directive.
10000 (0x02710) Internet Explorer 10. Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode. Default value for Internet Explorer 10.
9999 (0x270F)Windows Internet Explorer 9. Webpages are displayed in IE9 Standards mode, regardless of the !DOCTYPE directive.
9000 (0x2328)Internet Explorer 9. Webpages containing standards-based !DOCTYPE directives are displayed in IE9 mode. Default value for Internet Explorer 9.
Important In Internet Explorer 10, Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode.
8888 (0x22B8)Webpages are displayed in IE8 Standards mode, regardless of the !DOCTYPE directive.
8000 (0x1F40)Webpages containing standards-based !DOCTYPE directives are displayed in IE8 mode. Default value for Internet Explorer 8
Important In Internet Explorer 10, Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode.
7000 (0x1B58) Webpages containing standards-based !DOCTYPE directives are displayed in IE7 Standards mode. Default value for applications hosting the WebBrowser Control.