Hi,
I used fdisk and i made 4 primary partitions.
The first for windows, second for linux swap and the third for red hat 9.0.
I woul like to use the fourth for Slackware 9.1.
I tried to install it but i can't run it.
What should i do?

Don't create it as a Primary, but rather a Logical.. and what do you mean you can't run it.. You can't install it or you installed and it won't run? Errors if any?

For Slackware - typically, its not neccesary to create partitions in advance - for example in your scenario - the way I would do it would be to have Windows on first, Red Hat second and then leave some unpartitioned free space at the end of the drive for Slack to go on to - then simply boot from the Slack cd - at the partitioning section just type:

cfdisk

you'll see a list with the bottom entry being your free space - simpy choose how much of this free space you want to use for Slack's root partition - once youve specified a size just write the partition table to disk and carry on.

The message is - you can partition in advance - but often its not neccesary and if done incorrectly you can create more problems for yourself.

well, when i installed RH 9.0 i decided to use grub as boot loader. It recognized dos partition RH partition and swap partition. Then i rebooted and i installed Slackware. I think everything was ok but kernel(i selected the default one)
At the end it asked me to press control+alt+canc, but slackware was not on my grub choices. So i decided to add it with redhat config. When i tried to run it from grub an error said (ooops i don't remember).
(sorry for my english, i am italian)

ok, if you could post some more specific info for us, such as the contents of your /etc/lilo.conf, and fdisk /dev/hda -l that would make the advice we can give more specific.

basically, it sounds to me like you just need to edit your /etc/lilo.conf file to include an image of the slackware distro. here's an example:

other = /dev/hda1
label = DOS
table = /dev/hda
# DOS bootable partition config ends
# Linux bootable partition config begins
image = /boot/vmlinuz
root = /dev/hdb5
label = Linux
read-only
# Linux bootable partition config ends


in your case you would need to add another entry like this:

other = /boot/vmlinuz
boot = /dev/hda4 <--- insert the partition with slackware installed
label = Slackware
read-only

hope that helps... and in case it doesn't, here's a link w/ info on LILO - http://www.control-escape.com/linux/lilo-cfg.html

doh! just saw you're using grub....

From Red Hat can you post the output of:

fdisk -l /dev/hda

if your drives on the primary master channel - b if on primary slave , c secondary master, d secondary slave?

just did some research on grub for you, and it doesn't look too different from LILO. you want to find the menu.conf file, probably in /boot/grub, and here are some example entries:

The menu.conf file: this is used for booting multiple operating systems and menu building. Building the menu.conf file is not difficult. It uses plain English, as you will see in this section.

All the menu entries start with "title TITLENAME" without commas. You can set your TITLENAME to whatever you want.

To make the menu for booting Linux:

1. Set the title.
2. Set the root partition .
3. Set the kernel with right kind of parameters.
4. Boot

To make a working menu:

title Debian GNU/Linux 2.2 kernel 2.4.1
root (hd0,4)
kernel /boot/bzImage.2.4.1
boot
#----

(Hash (#) in front of a line is a comment.)

To make a menu for Windows or DOS:

title Windoze
rootnoverify (hd0,0)
makeactive
chainloader +1
boot
#----

the naming convention seems to be different, hda1 = hd0,0 hda2 = hd0,1 hdb3 = hd1,2 etc etc.

the main thing is still to make a new entry with root pointing at your slackware partition.

i got the info from http://www.linuxgazette.com/issue64/kohli.html which you can check out if you want.

The config file can be either:

/boot/grub/grub.conf

or

/boot/grub/menu.conf

something similar to this should be added (of course changing the particulars to match your configuration)

# For booting GNU/Linux
title Slackware-2.4.21-ac4
root (hd0,5)
kernel (hd0,1)/vmlinuz root=/dev/hde6 hda=ide-scsi mem=nopentium