More users are starting to evaluate and deploy Windows Vista, but they are showing more concern over perceived performance and patching improvements and the operating system's hardware requirements, according to a recent study.

The study, conducted by researcher Walker Information on behalf of IT services and product supplier CDW, shows found nearly 30% of respondents are using or evaluating Vista. The software shipped in November 2006 to corporate users.

The Vista Tracking Poll was the second conducted by Walker for CDW and is available for free but requires a user's email address to download. An identical survey was done last November.

The poll shows that 87% of 753 IT decision-maker respondents plan to eventually adopt Vista. It also found an 8% increase over the first poll in terms of deployments and evaluations of Vista by corporate users.

Since the first survey, 1% of users had completed Vista implementations and another 19% planned to complete their implementations in the next 12 months.

The survey also found that 6% of organisations are implementing Vista on a schedule that extends beyond 12 months, while 13% plan to start their implementations in the next year. Another 13% said they have no plans to upgrade.

"I don't think we were surprised by any of the data," says JoEllen Amato-Tuck, Microsoft brand manager for CDW. "It seems to be in line with what the first survey showed."

The second survey revealed that user concerns over hardware requirements being too excessive rose 9% over the first survey, from 28% to 37%. It was the fourth most common concern. The first was the expectation of bugs in the first Vista release.

A further 18% of users said they would need to upgrade 91% to 100% of their Windows-based hardware for it to be Vista compatible, a 2% increase over the first survey. Also, concerns that the benefits of adopting Vista are not clear enough rose 6% from 32% to 38%.

The concern that showed the steepest decline was having enough money to pay for a migration, which fell from 30 percent to 25 percent. Only 5 percent of respondents in the second survey said they had no concerns about Vista, down from 6 percent in the first survey.

The company plans a third survey sometime between September and December. CDW says the tracking poll will show over time how evaluation variables and deployment strategies are progressing.

The top benefit in both polls was improved security with 78% of respondents citing that feature. But the second poll showed that fewer respondents think Vista's performance and patching represent improvements in the software.

Positive perception of performance as a key benefit was down 7% from 63% to 56%. Patching fell from 31% to 25% and Windows Update from 36% to 30%.