Cannot install Intel 945 chipset drivers on Windows 7 on my Inspiron 9400

I have recently installed Windows 7, on my Inspiron 9400 and have had a few problems with the cpu usage shooting up to abouyt 80-100, slowing down to a snails pace and only coming back to normal after a restart.

I believe the issue is driver related, so I have tried many gpu drivers, with no joy. But when I try to install the Vista 32 driver for the Intel 945 chipset, I keep getting a message saying the "My system does not meet the minimun requirements". I have tried changing it do run in XP and Vista compatible mode, with the same outcome. I have also tried the drivers on Intel's download page with a similar result.

Any help would be apprecieted :)

Kind regards.