This is a common issue, particularly for large organizations that are
heavily invested in custom software. It can take a great deal of time
for organizations to test applications under a new environment, whether
that means a new browser or some other update to client software, and to
adapt their applications as needed.

Microsoft provides a utility that allows IE 7 to identify itself as IE
6. This can sometimes benefit users who need to interact with
institutions that, for one reason or another, have not yet made their
software IE 7-aware.

There's nothing magical about Microsoft's utility - it merely changes
the user agent string. You can change the user agent string to anything.
For example, this can sometimes make it possible for Firefox to work
with websites that specify Internet Explorer.

---
Leonard Grey
Errare humanum est