T3500 workstation - Alert! Error initializing PCI express NIC bridge.

Hi All, Hopefull you can help with an error I am getting.

When I first boot up the computer this error appears and reads:

Alert! Error initializing PCI express NIC bridge.

Strike the F1 key to continue, F2 to run setup utility, F5 to run diagnostics

When I hit F1 it boots up normally and all works fine. The computer is not on a network or the internet so I dont know if these functions work.

I found this on the dell solution network:

<ADMIN NOTE : Service tag removed per privacy policy>

But I either do not have or cannot find the 'onboard devices' option in the BIOS so I cannot do this fix. The machine is a Dell T3500 on XP pro.

Is this a driver/software issure or has some hardware failing or failed? Any help with this error would be much appreciated.

Thanks for you help in advance.....