Extending the use of laptops two years beyond the traditional three-year lifetime cost companies an average of US$1,050 per machine -- more than the replacement cost, the Northborough, Mass.-based firm found.

The added costs include a significant boost in repair costs due to old age and the end of three-year warranty periods, it added.

The use of outdated equipment also costs a company about $9,600 per laptop user in lost worker productivity over the two-year period, the study found.

Jack Gold, president of the consultant, said many companies are keeping a lid on new purchases because of the recession.

He added that some forward-thinking companies have taken the strong step of of some users with less expensive smartphones or other handheld devices. Such devices can be far more cost-effective for users who were using laptops mostly to access e-mail. "If you only read email, you can eliminate the laptop," Gold said.