I have windows in my pc, installed Suse Linux into a partition, booting with Lilo, later on I began having problems with Windows, related to windows problems,

Now I want to format the partition, reinstall windows, the problem is that i already tried it in another computer and lost the lilo boot capability, my mistake there was no to make a boot disk for linux,

Now the questions is, how can I install Windows into the partition (primary) without affecting windows???
or is it really necesary afterwards to use the boot disk???

An extra thing is does it cause any problem if I use the same ip address in windows and linux for my pc..... have two network cards....

An also is it posible to be use two network cards at the same time, both connected to the network...... I suppose that it will make my transfer and all that a little faster... just a thougt... : )

You need a boot disk or any Linux installation cd to restore Lilo. You don't need a boot disk made for your distro, just ANY Linux boot disk (or a one-floppy distro).
There's no problem when you use the same IP in Windows and Linux (it can make problems only when they run at the same time ).
You can use 2 nics, but transfer is usually done using only one interface (read Advanced-Routing HOWTO for details). To configure second nic use
ifconfig eth1 ipforsecondnic

Is there any syntax to use to restore Lilo, after windows has been installed....

and is lilo compatible to boot winXP

Yes it's comatible, and the syntax (if you can get to a linux command prompt) is "/sbin/lilo". Gotta love that.

Cool

<edit>
Almost forgot to tell you how to use lilo to boot it...

Place this line (replacing the a and the 1 with the correct letter/number of YOUR drive/partition) into your /etc/lilo.conf file:

other = /dev/hda1
table = /dev/hda
label = Winbloze (or whatever you would like to call it )

and then run /sbin/lilo from a linux command prompt.

Cool

But if you had a working system (working Lilo),
/sbin/lilo
will be enough. It's that simple if you're using a boot floppy. If you have a cd, usiually it creates its own filesystem, so you need to
1) mount your / (root) Linux partitions from hd, you can do this:
mkdir /mnt/linux
mount -t ext2 /dev/hda5 /mnt/linux
In this example I assume your SuSE is using ext2 filesystem and rouu partition is /dev/hda5
2) chroot to set / directory to your own / (seems compilcated, but it's easy):
chroot /mnt/linux
3) and now lilo:
/sbin/lilo