LE 6.4cs9 and "Conflicting with other CPU tasks" errors

[wsv3036]

Sorry I can't get all my information. The computer in question is not online and not in the same building. sorry this is the best i can do for specs

Widnows XP Pro with service pack 2

AMD Athlon x2 3800+ socket 939
1 GB of RAM one from 1 chip
IDE channel 1 = DVD+/-RW DL drive
IDE channel 2 = Maxtor 160GB

Motherboard
Mach Speed MK8-939A VIA chipset
(RAID disabled in BIOS)

1 AGP nVidia 5500 GX graphics card

1 1394 adapter in a PCI slot

Digi 001 card in another PCI slot

External 160GB firewire drive

So my problem is after building this system i installed ProTools 6.4 with the cs9 update and the interlock driver update. when trying to record, nothing happens. the program flinches and then does nothing. when i tried to play an already recorded session i get "Audio processing is conflicting with other CPU tasks" errors. i also noticed that the CPU meter in the system usage window is going crazy. never staying in the same place. I used to use this same digi001 unit on another PC that i sold and upgraded to this PC. the unit served me well for about 2 years. i just cant seem to get it to run on this one. Please help.