Taskmgr.exe 100% CPU Usage

I have 2 IBM servers Intel Xeon Dual core with > 2gb RAM.

the problem is that Taskmanager uses one full core when i open it.
The same happens when i copy files in the explorer.

_{(source: bghupdate.com.ar)}

Threads in procexplorer http://www.bghupdate.com.ar/chasco/threads.jpg

OS: Windows 2003 Server

Things i tried:

1. Installed all updates
2. They has kaspersky anti virus and they previously had Nod32.
3. All drivers installed OK.
4. All unused devices are disabled in the bios. (Planar SCSI, Serial Ports, LPT, Audio, Unused networks)
5. Reinstalled win 2003 SP2.
6. No conflict in drivers
7. Tried opening via remote desktop and the problem continues.
8. Updated Bios and Scsi firmware to latest versions
9. Updated all drivers from IBM

The cpu utilization is in the Kernel Times (Red in taskmanager)
If i open Proces Explorer and i navigate to the threads consuming CPU the stack traces ends always in "NtkrnlPA!UnexpectedInterrupt", all threads stacks end in "UnexpectedInterrupt"

ntoskrnl.exe!KiUnexpectedInterrupt+0x48
ntoskrnl.exe!KeWaitForMutexObject+0x20e
ntoskrnl.exe!CcSetReadAheadGranularity+0x1ff9
ntoskrnl.exe!IoAllocateIrp+0x3fd
ntoskrnl.exe!KeWaitForMutexObject+0x20e
ntoskrnl.exe!NtWaitForSingleObject+0x94
ntoskrnl.exe!DbgBreakPointWithStatus+0xe05
ntdll.dll!KiFastSystemCallRet
kernel32.dll!WaitForSingleObject+0x12
taskmgr.exe+0xeef6
kernel32.dll!GetModuleHandleA+0xdf

Any help would be appreciated!