Dell has acquired infrastructure consultancy ACS, hoping to boost its low earnings by helping businesses upgrade to Microsoft Vista.

The PC maker bought the UK IT services firm as part of its plans to offer consulting to large businesses as they upgrade to Microsoft's new Vista operating system.

ACS of London is a privately held firm that provides infrastructure consulting to businesses listed on the FTSE 100. Dell did not disclose the deal's cost, but said it would retain all ACS employees.

Dell will use ACS to offer IT support earlier in the planning stages of customers' application deployments, such as migrating to Microsoft Vista, according to a statement from Stephen Murdoch, vice president of solutions and services for the Dell EMEA division.

Business customers have been demanding better services in virtualisation, security and Microsoft products. Dell hopes to meet that need with ACS, which specialises in tailoring software installation routines to meet customer's needs. Dell now plans to extend that "application packaging" service outside the UK., offering it to customers worldwide, it said.

The move is also seen as another step in Dell's effort to rescue its slumping financial results by improving customer service. The company has missed its earnings targets for recent quarters, was embroiled in a massive recall of laptop PC batteries in August and is being investigated by the US Securities and Exchange Commission for its financial reporting practices.

The company has made several changes to recover, launching a line of computers based on chips from AMD instead of Intel and pledging to spend $100 million (£52.8m) to improve customer service by opening new call centres.