Microsoft is pushing desktop virtualisation as a way of making Windows 7 play nicely with old applications, especially those written for Windows XP. So now that the technology has been "blessed" by Microsoft, should we expect a desktop virtualisation boom?

Probably not, most experts agree. "Adoption is ramping up slowly due to complexity and cost," according to a recent presentation by Forrester Research.

That said, though, there will likely be an uptick in the acceptance of desktop virtualisation for a couple of reasons. First, more vendors are offering virtual desktop infrastructures, which give each end user a private "desktop". VDIs use the same kind of hypervisors that allow many virtual machines to run on a single physical host. But rather than running five- or 10-server VMs on one physical server, a VDI can run 50 PC operating systems, each of which serves a single end user.

Desktop virtualisation at a glance

Definition: A computing environment that is abstracted from the end user's PC. It consists of an operating system, applications and associated data.

Type 1: Local desktop virtualisation. The entire desktop environment - essentially a very large file - executes in a protected "bubble" on the end user's PC. Vendors in this market include Microsoft, MokaFive, Parallels and VMware.

Type 2: Hosted desktop virtualisation. The desktop environment executes on data centre servers, alongside other virtual machines. Vendors in this market include Citrix, Desktone, Microsoft and VMware.

ROI: The nine-month ROI that vendors tout may actually be more like three or four years, because the upfront infrastructure and licensing costs far outweigh the upfront benefits. So include other benefits, such as increased security and lower support costs, to make your case for virtualisation.

Prediction: "The revolution will take years, but virtualisation is the future of the corporate PC."

Source: Forrester Research.

The other big change is support for peripherals, multimedia and other web- and PC-focused technologies. Those haven't been available to users of shared-image terminal-services types of systems - that is, traditional desktop virtualisation set-ups - but nowadays most other users think they can't live without them.

"Improvements in the user experience are really a big deal in making desktop virtualisation more acceptable," says Andi Mann, an analyst at Enterprise Management Associates (EMA).

Giving end users all the benefits and all the capabilities they'd have on stand-alone machines - including the ability to add or update their own browser plug-ins, media players and other "extraneous" software - could overcome most of the objections of business units that have kept virtual desktops out of the mainstream user base, Mann says.

Updating Old PCs

The fact that some companies are unwilling to upgrade their PC hardware so that it's capable of supporting Windows 7 could also help make virtual desktops more popular, according to Chris Wolf, an analyst at Burton Group, now part of Gartner.

Implementing Windows 7 requires upgrading hardware, updating custom-built software, training end users and updating the security on PCs running the new operating system. That process can be so expensive and disruptive that many companies are asking consultancies like Burton Group to evaluate whether it makes sense to leave end users on their present hardware and upgrade them by running Windows 7 as part of a virtual-desktop connection, Wolf explains.

What IT managers want from desktop virtualisation

Top Five Expected Benefits

IT managers expect to cut costs when they implement desktop virtualisation.

1. Reduce hardware costs

2. Reduce administrative/ management costs

3. Improve flexibility and agility

4. Improve staff mobility

5. Improve security and compliance

Top Selection Criteria

IT managers want to select desktop virtualisation products that will be easy for employees to use and easy for IT to manage.

1. Ease of user for end users

2. Ease of management

3. Support for systems/apps

4. Scalability

Source: Enterprise Management Associates Inc. survey of 102 IT professionals who are familiar with desktop virtualisation, August 2009

Connecting end users to a new operating system on a server can more than double the life of an ageing PC while still giving end users all the power and support for new software and new technology they want, according to Peter Graves, CIO at Independent Bank Corp.

About 90% of Independent Bank's users already have shared-session virtual desktops from Citrix Systems, and Graves says that adding the other 10% will be no great leap once the technology supports the customised software and peripherals they need.