I just upgraded hardware from a single processor motherboard to a p4 w/hyperthreading. Since it is still a single processor, Windows XP is still using the single processor HAL even though both logical processors are listed in device manager.
I tried booting with the XP cd and using the recovery console to manually rename the hal.dll and copy in the halmacpi.dll from c:\windows\servicepackfiles\i386 into c:\windows\system32 and renaming it to hal.dll.... All that accomplished was windows not even getting started to load... it doesn't even bring up the blue progress bar.
That has worked with Windows NT in the past if I did this type of situation (I either moved the drive to another PC to copy the files, or used a third-party program that can read NTFS in DOS).
What else can I do? I also tried manually updating the driver in device manager and pointing it to te acpi.inf in c:\windows\servicepackfiles\i386. This did not give me the option to choose the multiprocessor HAL.
Thank you for your time!