installing XP in Acer Aspire one

Made a mess editing boot.ini of my dual-boot Acer Aspire One netbook so that XP boots first & now will not boot in XP, giving error:-

"Windows root>\system32\hal.dll is missing please re-install a copy".

I cannot install "hall.dll" but, I have XP home on a stick.

1. Can I reinstate the ACER now to manufacturer's condition? or

2. How do I go about reinstalling XP? Note that it boots in Ubuntu 11.04 OK, but not in XP.

Thanx Steve,

Is it not possible to install XP as is on the USB stick?

Slipstream never worked for me, tried many times.

If I can install straight from the stick then I can install SP3 etc after.     ....nick

Luckily on the last reboot I noticed a linux menu with 4-5 option, & one was "Acer eRecovery Management" which did the XP installation all on its own even giving the option to save & install all files & programs.

Then, I went & installed Ubuntu 11.04 from my USB stick but, & now on boot-up it does not give the XP boot.ini Menu but, the "GNU GRUB" menu with 11 choices for Ubuntu (default) or XP, which is very complicated.

The rub now is how do I change the default to XP?

Any easy way?

SOLVED

by These:-
You can change the default menu entry to boot by either going to the

/boot/grub/grub.cfg file and near the top of the file changing the entry: set

default="0" to another number.Count the menuentry lines until you get to xp.

Put that number in the set default. Grub counts in this case from zero, so if

your xp is the 5tn entry, put a 4 there

.

To keep grub with default boot set to XP, you may use the GRUB_DEFAULT option
on /etc/default/grub (as already said by yancek) or change the
/etc/grub.d/30_os-prober file order.

Then :-
sudo gedit /etc/default/grub       .....This brings up grub in editor & change to what ever No. you require.

[U]sudo update-grub      ..........this in a new terminal updates Grub.