My company has a few web apps which require Internet Explorer . Rather than allow users to use other browsers (which would cause errors) there is a browser check when the user pulls up the login screen, and if they are not using IE they get a message saying to install it, or what have you. Recently we started running into some issues whereas some users are using IE7 but failing the browser check. Useragentstring.com would show the following: We've run into similar issues like this in the past, and we were able to remove the incorrect info, or update the registry with the correct agent string in order to resolve the issue. However, when searching in the registry of affected users the above agent string is no where to be found, not even in the normal agent string locations. Besides the registry, where else could the string be pulled from?