Unsurprisingly in order to utilise both cores you need to be running an operating system which supports multiple CPUs. That support is in the latest versions of Windows and Linux. Support is there in Windows XP, but there were various bugs found along the way (eg Dual core based gaming machines actually ran more slowly if both cores were in use) but these had been fixed by the time the final service pack (SP3) was released.
As you'd expect the embedded version of XP on the t5730 does not include the dual core drivers. (Why included unneeded drivers?). If you're intending to just beef-up the processing power of an otherwise unaltered t5730 thin client then you'll have to add the dual-core support by adding/replacing certain system files/drivers.
Google can be your friend here....for example from http://incore.net/winxp-multicpu/ (now a dead link?):
To switch to Multiprocessor support need to modify some system files. There are three files involved in this in your Windows/system32 directory:
The versions you need may be found in Windows/ServicePackFiles/i386:
i.e. It looks like what you need to do is to back-up the three files (HAL.DLL etc) and then copy over the the three new files renaming them on the way:
halmacpi.dll -> hal.dll ntkrnlmp.exe -> ntoskrnl.dll ntkrpamp.exe -> ntkrnlpa.exe
You should find the relevant drivers in an up-to-date XP system or in the latest Service Pack.
Any comments? email me. Last update April 2012