Vista - Service pack 1 Problem

When i try to install Service pack 1 it gives me a message:
"The Windows Vista Service pack Installation cannot proceed until you computer is restarted. Please restart you computer and try again"

I have restarted many times and still get the same problem.
I am running a legit copy of Vista Home premium 32bit
No other programs are running when i start the service pack install.
system specs:
Manufacturer: HP-Pavilion
Processor: AMD Phenom(tm) 9500 Quad-Core Processor (4 CPUs), ~2.2GHz
Memory: 3070MB RAM
Hard Drive: 489 GB
Video Card: NVIDIA GeForce 9800 GT
Monitor: 22' Widescreen ASUS LCD/17' Viewsonic LCD
Sound Card: Speakers (Realtek High Definition Audio)
Speakers/Headphones: 5.1 Logitech Surround Sound Speakers
Keyboard: Logitech G15
Mouse: USB Root Hub
Mouse Surface: Desk
Operating System: Windows Vista™ Home Premium (6.0, Build 6000) (6000.vista_ldr.071023-1545)

Any help will be greatly appreciated