HP's client business has seen its revenues and net earnings fall during the three months ending January 31st 2016.
PC, notebook and print sales were down across the board.
HP Inc president and CEO Dion Weisler said there are tough times ahead.
"We have a clear strategy that leverages our strengths, and we are focused on execution, taking cost out of the business and delivering innovations that will amaze our customers and partners," he said.
"Although we have some tough quarters ahead, I am confident in the future."
"We have not yet seen the anticipated stimulation of demand [from Windows 10] that we would hope for," he added in a conference call. "Our PC lines are being redrawn at the moment, and the goal has been to gain profitable share."
He also said HP is trying to create 'new categories' to stimulate demand.
Personal systems net revenue at HP Inc was down 13 per cent year-on-year, while notebooks units were down eigh per cent and desktops units fell 13 per cent.
Printing net revenue was down 17 per cent year-on-year, with commercial hardware units down 15 per cent and Consumer hardware units down 23 per cent.
Overall, HP Inc generated $592 million in net earnings in Q1 2016, a fall from the $1.3 billion it generated during the same period last year.
Revenues fell year-on-year from $13.8 billion to $12.2 billion.
HP Inc also said that 3,000 members of staff will leave the company at the end of the year, following its initial job cut announcement last year.