About 4,000 contractors from a number of firms will be affected by the work stoppage, scheduled for 24 June to 12 July.
Those contractors handle aspects of HP's Web site and other IT infrastructure tasks overseen by HP chief information officer Bob Napier, according to HP spokesman Arch Currid.
A small number of essential contractors will continue working during the stoppage. HP is in the process of re-evaluating its contracts and cancelling those it no longer needs, Currid said.
The move comes as HP focuses on cost reduction following its acquisition of Compaq. HP chairman and chief executive officer Carly Fiorina has pledged that HP and Compaq will cut their combined operating costs by $2.5bn (£1.7bn) by October 2003.