However, Gartner believes Microsoft is giving mixed signals on the legality of virtualizing IE with third-party virtualization software.

"While we have not heard of any formal legal action by Microsoft toward vendors or customers of application/IE virtualization solutions, Microsoft's position is that it violates its licensing terms," Gartner writes. "According to Microsoft, IE is only licensed as an integrated component of the OS (either originally or via updating earlier versions of IE on an OS) and IE is not licensed for use on a stand-alone basis."

If customers really want to pursue virtualization of IE on Windows 7, they should seek amendments to license agreements with Microsoft to specifically allow such activity. In addition to examining legal risks, customers must also consider the technical risks of running virtualized instances of IE on Windows 7. These risks could add to the security problems already inherent in running an out-of-date browser.

"Microsoft support for IE6 will end 8 April 2014, the same day Windows XP support ends," Gartner writes. "If Microsoft releases any security fixes for IE6 before then, the IE 'bubbles' may have to be rebuilt to be secured, and there is the possibility of new problems being introduced. Organizations that continue running IE bubbles after the end of support may similarly be vulnerable to security problems."

In general, Gartner says customers should not standardize on one browser, to avoid problems such as these. But the analyst firm also says Microsoft may be acting against its own interests in throwing roadblocks in the way of IE6-using businesses.