With the full availability of Windows Vista, IT departments are likely to feel pressure from staff to upgrade sooner rather than later, according to a report published by analyst firm Gartner. The company also warned that businesses should carefully identify the Vista features they need to choose the edition that suits them best.

Vista has been available in shops and pre-installed on systems since 30 January, and more than 70 percent of new consumer PCs are expected to ship with it during 2007. Many businesses plan to defer deployment until the first service pack ships later this year, but staff impressed with Vista’s media handling capabilities at home are likely to bring the new operating system “in through the back door” without IT approval, Gartner said.

This was the primary way that Windows 95 entered the enterprise, according to Gartner. The firm suggested that IT departments should use the opportunity afforded by such installations to help them understand how Vista will work in their environments.

But IT departments also need to be aware of the differences between Vista editions. Employees are likely to have purchased the Home Premium version, which includes consumer features such as Windows Media Center, but lacks others such as Vista’s Networking Center and Remote Desktop Connection.

System vendors shipping Vista PCs are largely pre-installing the Vista Business edition, which includes the business features mentioned above but not all features found in the Vista Ultimate or Vista Enterprise editions.

Vista Enterprise is available only to volume customers that have signed up to Microsoft’s Software Assurance subscription licensing terms. It includes the BitLocker hard disk encryption tool, multi-language support and Microsoft’s Subsystem for Unix-based Applications (SUA), which enables Unix applications to be compiled and run on Windows systems through Posix API support.

The BitLocker encryption tool is potentially an attractive feature for companies with mobile workers, who may be carrying sensitive information on laptops. The downside is that firms must either sign up for Software Assurance to get it, or purchase systems with Vista Ultimate, which carries a much higher price tag than Vista’s Business edition.

However, Gartner described BitLocker as “good, but not great”, and compared it unfavourably with encryption tools from other vendors. One is Pointsec Mobile Technologies, which has criticised BitLocker because it protects only the boot partition on which Windows is installed. Pointsec’s own products support a separate encrypted partition for data files and leave the operating system and applications unencrypted.

Another problem highlighted by Gartner is that even large organisations will have to activate the copies of Vista they deploy, usually via a key management service operated from a local server. This does not apply if PCs have been shipped with Vista pre-installed, in which case the operating system should be ready activated.