Microsoft's wish that consumers purchase the premium versions of Windows Vista rather than the most basic version of the OS may be coming true, according to the findings of a research report released Thursday.

Research from Current Analysis Inc. for the week ending February 3, which covers the first five days Vista was available to US retail customers, shows sales of PCs with Vista Home Premium preinstalled comprised 70 per cent of PC unit sales in the US retail market, while sales of PCs with Vista Home Basic accounted for 22 per cent. Windows Vista was released to consumers on January 30.

However, sales of PCs with the most full-featured and expensive consumer version of Vista, Windows Vista Ultimate, were lackluster in the first week, accounting for a mere 1.2 per cent of PC sales. However, Samir Bhavnani, the Current Analysis research director who wrote the report, said he expects this will eventually change.

"You can expect over time that Ultimate will become a bigger part of the overall mix," he said. The release of Vista boosted overall PC sales, giving the PC market the best week it's had in four years, Bhavnani said. PC unit retail sales increased 173 per cent for the week ending February 3 compared to the previous week, and were up 67 per cent year over year, according to the report.

And the increase occurred at a time when retailers weren't even promoting Vista to customers as much as they were promoting another consumer product, he said.

"Most of the retailers last week were focused on selling HDTVs because of the Super Bowl," he said. This week Vista has been more top of mind with retailers, so he said the strength of PC sales during Vista's first week should be sustained over its second week of release.

Still, if Microsoft had gotten Vista to market before the busy holiday shopping season in November and December as originally planned, Vista would have had an even more impressive launch, Bhavnani said.

Out of the PC vendors selling hardware that supports Vista, Hewlett-Packard Co. fared the best in the first week, according to the report. HP accounted for a 54 per cent share of Vista Home Premium sales and a 53 percent share of Vista Home Basic unit sales. The week prior to the introduction of Vista, which ended January 27, HP computers represented 33 per cent of all PC sales.

As for the long-term sustainability of Vista PC sales, that remains to be seen, Bhavnani said. "We won't know the answer to the question until we look at the first half of this year relative to the first half of the year last year," he said.