Windows 7’s Costly Compatibility Issues

Microsoft officials proudly proclaim that the Release Candidate (RC) landmark of the Windows 7 development cycle represents a good time for businesses to start evaluating the new operating system in a production environment. While the code made available up to this point seems strong enough to warrant this level of in-depth appraisal, I suspect IT implementers will quickly find too many unanswered questions to gain a firm grip on the role the new operating system can play in business, or if it has a role at all in the near term.

In my few days with the new version, I’ve found that the release candidate (Build 7100, available now to MSDN and TechNet subscribers and to the public from 5 May) installs and runs quickly and efficiently; is highly polished for this stage of development; already supports a wide array of hardware; and is obviously rich with security, connectivity and usability features when compared with either Windows Vista or XP.

But with the issues of application compatibility and licensing still not addressed in a way that companies can test, and with Windows 7’s deep ties to the forthcoming Windows Server 2008 R2 to consider (not to mention the moribund economy), potential implementers may find it difficult to find the value in the new OS, despite its obvious improvements.

Application compatibility, or lack thereof, was one of the torpedoes that sank Windows Vista; too many users and organisations found that operating system’s security implementations broke mission-critical legacy applications or devices. As Windows 7 is built with the same security fundamentals in mind (including User Account Control, Address Space Layout Randomisation and Kernel Patch Protection), Microsoft had to address the issue directly with the new OS, to ensure a seamless transition to the new platform for customers.

The announced solution—Windows XP Mode for Windows 7, or XPM—runs a virtualised instance of XP Service Pack 3 within Windows 7. Customers who hold licences for the right version of Windows 7 (Professional, Enterprise or Ultimate) will be able to download the software, which includes a copy of Windows XP SP3 and a licence to run it virtually. Integration with the host operating system should be present, and users can expect to be able to launch virtualised applications directly from the host interface (similar to what one could do with VMware Fusion’s Unity mode on a Mac).

As pointed out here, XPM is fraught with security concerns. Indeed, it appears that the XPM VM needs to be managed as a separate node on the network, and will require its own anti-virus, patch management and management software. But that’s just the tip of the iceberg.

So Many Questions

I haven’t received a copy of the XPM beta code, yet, so I find myself full questions even beyond these already sticky issues. Does the XPM instance itself need to be joined to the domain, and what does that mean for Client Access Licenses? Do the host and virtual instances need to be managed separately via Group Policy? Will security patches for XPM instances stop coming in five years, even though Windows 7 is protected for much longer than that?

With XPM, Microsoft has thrown up its hands and effectively proclaimed, “We can’t support these applications going forward, nor do we want to try.” I understand that perspective, everyone wants to move forward unencumbered, I just can’t grasp the approach.