On February 2, 2010 I purchased a HP Pavilion A4316f bundle (included monitor). When I booted it up for the 2nd time, it took 55 minutes to boot. Thereafter it took an average of 20 minutes to boot. After 4 e-mail communications with their support and complying with their requests, I got the boot down to 18 minutes.
I contacted Staples where I purchased the system and they told me to bring the tower (computer) in and they would swap it out. I did so and was very pleased with their attentiveness.
I currently have a new computer and it takes 15-18 minutes to boot. I do not intend to ever purchase another HP product.