I have a HP p7-1297cb. Win7 Home Premium?

Are we talking about case and system fans or the CPU fan?

Case and System fans should always run, make sure they are plugged in. If they are I would get your PSU (Power Supply Unit) tested as well as replace the fans. If the 3.3v is out on your PSU there may not be enough power for them. This will not be the issue though if your fans are using Molex connectors instead of riser connections. If they are Molex connections I would just replace the fans and see if new fans operate correctly.

If it is a CPU fan we are talking about and since this is an AMD system we are talking about, correct? Have you tried connecting a different CPU cooler with fan and see if that one runs? If it is not your cooler's fan it could be that the cool and quiet function of the bios is operating improperly. Although I have seen cool n' quiet stop the CPU fan in the past but usually only on systems in cool environments, although I don't trust that and I would replace the mainboard.

Most likely though if your fans are connected correctly it is just they were cheap and/or non-functioning when you got the system. Try replacing them first, most case fans can be found for around 5~10 bucks.

I don't think controlling the fans or making them faster really helps. I know on my macbook people told me to turn up fan speed if I didn't want to keep hearing my fan run all the time on my macbook and when I used software to do that my macbook crashed for the first time ever. Tho desktops might be different.