Dead Mobo, New Mobo, Slow load Windows, CPU Idle at 50%

Alright, I had a motherboard that died (ASUS P4S800) I needed a quick fix so I ran to Compusa and bought a new motherboard (Abit VT7) After putting it in I repaired windows, but everything was running slow as far as boot up. The Windows black screen with the blue bar goes quick and fine, and then once the screen blinks and the mouse appears on black it takes a while before the windows login screen (I have it set to autologin with tweakui). Then it takes a while before it says loading your settings or whatever, then finally it boots into windows.

Right now I'm idling and running CPU at 53%. The load up and idle cpu were the same when I ran msconfig and rebooted into diagnostic mode. Next I ran disk defrag and check disk, still no fix. So I reformatted the disk and reinstalled windows. Same story. Everything runs pretty alright, but the cpu rocking the 50% area is no good.

Under Processes in task manager, System Idle Process is at 88-90% so obviously something is off here. Anyway, I've got a new mobo (Asus P4P800SE) coming from newegg and when it gets here I'm returning this Abit board. However I'd like to find out what is up with this crazy cpu idle. Any suggestions or things I should try and do?

here's the system specs
abit vt7
p4 2.8GHz Prescott
1GB Kingston DDR
80GB Western Digital (system) ATA
160GB Seagate (storage) ATA
Nvidia Geforce FX 5200

I ran FreshDiagnose's CPU Benchmark and it ranked my processor lower than all the others on the chart. Even lower than the Celeron 700MHz. All other benchmarks ranked as they should have.

Please help me guys! Thanks!