BSOD error on Windows 7 ultimate

BUG CHECK STRING = DRIVER_POWER_STATE_FAILURE
BUG CHECK CODE = 0x0000009f
PARAMETER 1 = 0x00000003
PARAMETER 2 = 0x85f05420
PARAMETER 3 = 0x82962ae0
PARAMETER 4 = 0x85aa2ab8
CAUSED BY DRIVER = ntkrnlpa.exe
CAUSED BY ADDRESS = ntkrnlpa.exe+dcd10
FILE DESCRIPTION = NT Kernel & System Microsoft® Windows® Operating System Microsoft Corporation 6.1.7600.16385 (win7_rtm.090713-1255) 32-bit C:\Windows\minidump\111109-22198-01.dmp

This is the BSOD mini dump that I have been getting recently. I was wondering if anyone had any ideas what would cause this. I just did a clean install of Windows 7 ultimate 32-bit. I don't do a lot with this PC. Mostly surf the web and that's when it happens. My only guess is that the power supply is failing and I need a new one. I wanted to check here and see if anyone else had some other idea before I bought a new one.

I've seen this a dozen times and it always was due to outdated or incompatibile drivers. It never had ANYTHING to do with power, sleep mode, etc.

1). Use Microsoft Windows Update, check all critical and look in Optional for driver updates. Reboot.

2). Go to the manufacturer's website and see if they provide Windows 7 drivers. Update everything unless you specifically remember updating that driver with the Windows Update program.

3). If your manufacturer does not offer Windows 7 drivers, there are a couple tricks. You can either google the name of the computer and look for people who have released Windows 7 drivers; visit each component manufacturer's website (nvidia, intel, broadcom etc.) individually and download the drivers for your device; or use your manufacturer's windows vista drivers and pray for the best.