Acer, one of the world’s largest PC makers, told the Taipei Times that it was revising its sales growth rate down because the demand for Microsoft (MSFT) Vista was below expectations. Commercial sector sales have been especially slow.

The commercial sector is the greatest strength of US PC giant Dell (DELL). Assuming that it is encountering an environment similar to Acer’s, it may mean that the turnaround that the market is counting on will be slow to bear fruit. Acer’s sales tend to be strongest in Europe and Asia.

With Dell’s shares up 20% this year, any leak in Vista demand could create a very tough headwind.

Douglas A. McIntyre