First thankyou all for writing me about the boot cd of redhat. As i said i have redhat 8 now the problem is another thing. As i select automatic partition or any other option it has always the same problem. I don't remember exactly the phrase but i think it is:can't allocate requested partition.I have 3 partitions and one of them is for linux and i have information that can't be deleted this is why i can't make a new partition or format my computer. I have partition magic so if someone can help me please do it.

Run the Install again; select the option "fdisk" when it comes up. Type "p" for "print partition table (i.e., to the screen)". Write down the details it shows you. Type "q" to quit from fdisk. Please post what you wrote down. If you already have a partition reserved for Linux, and you don't need to resize it, you probably don't need to run partition magic.

if uou know the partition eg hdxX add this line in /etc/fstab /dev/hdxX mntpoint type nooauto,owner,rw,user 0 0 replace /dev/hdxX with appropriate device mntpoint with appropriate directory type with fs eg vfat for fat32 oe ext3 noauto will not mount it at boot but the user who will mount it will access to read or write in it command for mounting after writing the line will be mount mountpoint for extra caution take your hdd to another comp having lignux and follow the procedures given above and copy important data from that that mounted part to a cd or another hdd