How to change between hals without reinstallation / repair.

Typical (and worst possible) method to change hal is to repair or reinstall whole system.
Task a little time consuming and not particulary healthy for system itself. Here is better one,
suggested by me few times on this forum. This mini-guide is based on w2k+sp3, but with
minor modifications should apply to XP (directories, different cab, maybe some tinkering with
XP's famous anty piracy *cough* protection).




from \WINNT\Driver Cache\i386\sp3.cab (I assume sp3 is installed), extract following
files:

halacpi.dll
halaacpi.dll
hal.dll (and rename to halpic.dll)

copy those files to \WINNT\system32


add to boot.ini floowing lines, remembering to keep numeric values (denoted as 'x') with proper values, specific to your system
multi(x)disk(x)rdisk(x)partition(x)\WINNT="ACPI+AP IC" /fastdetect /hal=halaacpi.dll
multi(x)disk(x)rdisk(x)partition(x)\WINNT="ACPI+PI C" /fastdetect /hal=halacpi.dll
multi(x)disk(x)rdisk(x)partition(x)\WINNT="non-ACPI" /fastdetect /hal=halpic.dll

Now you can switch in bios ACPI and APIC options to you liking.


after you succesfully boot you system, you can update driver under Manage -> Device Manager -> Computer,
so default hal.dll is updated properly (although it's not required). After this step, you can use
default boot option again.



Remarks:

- in case M$ releases some pre-sp4 hotfix with modified hal files in some future, you should take specific files from that hotfix.


I'll update this guide (or add separate) with short sysprep manual, which can be used as tool to force full pnp rescan of system and as tool to change ide drivers between different mainboards.

I take no responsibility for all above, if you screw your system