Enterprises addicted to Microsoft's nine-year-old Internet Explorer 6 (IE6) browser are having a tough time migrating to Windows 7, an analyst said today.

And although Microsoft has made it clear it wants IE6 dead and buried, the company needs to help solve a problem it created when it released the non-standard browser, then pressed businesses to develop IE6-specific applications, said Michael Silver of Gartner.

"Microsoft would rather put the non-standard browser technology behind it," Silver said in a recently published research report.

Easy for Microsoft to say; it doesn't have to deal with the IE6 fallout.

According to Gartner, IE6 compatibility problems will cause at least one-in-five organizations to take longer than expected or spend more than they budgeted for their Windows 7 migration projects.

"Microsoft needs to explore all avenues that could ease the transitions away from IE6," Silver added as he spelled out ways the company could lower barriers to Windows 7 adoption, something obviously in its interest.

The latest statistics from Web metrics company Net Applications pegged IE6's usage share at 15.6%, which means it's the world's third-most-used browser edition. Many of the holdouts are enterprises locked into IE6 because the commercial software or home-grown applications they use work only in that browser.

Organizations running IE6 have told Gartner that 40% of their custom-built browser-dependent applications won't run on IE8, the version packaged with Windows 7. Thus many companies face a tough decision: Either spend time and money to upgrade those applications so that they work in newer browsers, or stick with Windows XP.

But Windows XP won't live forever. Microsoft will retire Windows XP from all support in April 2014, forcing businesses to abandon it or risk running an operating system vulnerable to attack.

Fixing homemade applications so that they run in IE8 is the surest solution, but also the most expensive. And every temporary workaround has a downside, said Silver.

The most promising of the latter is to use application virtualization tools to virtualize only IE6 -- not, as in OS virtualization, an entire operating system -- so that it can be run in Windows 7.

But Microsoft opposes IE virtualization because it says the process violates licensing agreements. The stance hasn't been tested in court -- Microsoft hasn't sued vendors like VMware and Symantec that provide application virtualization tools -- but the uncertainty make companies jittery.

"It's ironic that Microsoft would oppose methods that would help organizations accelerate the move to Windows 7," said Silver in his research note. "Microsoft must do more to help organizations with their IE6 problems that Microsoft helped cause."

If Microsoft doesn't want customers virtualizing IE6, then it should help out in other ways, perhaps by heavily discounting or even giving away Windows Server 2003 and associated client licenses so that companies can access IE6 -- and only the browser -- through April 2014 using Terminal Server.

"Organizations need to resolve IE problems and begin their migrations to Windows 7 as soon as possible," said Silver "And Microsoft needs to do more to help."

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@ix.netcom.com.