I want to know if I can dual boot two linux distribution such as Red Hat and Ubuntu or SUSE please help needed

yes you can. most modern installers will handle this as part of the normal process.

The record is over 100....Search here for Saikee and look at his tutorials.

My site also has some stuff on booting.

I don't think there is a limit on how many systems we can boot with Grub.

If there is such a limit then I have given up at about 150 systems. However as we can "nest" Grub menus together like a network or a chain and if one menu boots 150 then about 7 menus can fire up 1000 systems.

I am reasonably certain the sky is the limit as far as Grub is concerned.

Mind you all boot loader menus can be nested (for example one can boot to a NTLDR, then jump to a Lilo , then hoop into a Grub, then back to another NTLDR in an endless loop and select any system to boot on its way) so there has never been a limit of how many systems a user can boot.

The word "dual boot" is a funny term to me because I haven't met one boot loader that only boots 2 systems. The minimum is 4 by Dos's MBR because it can boot from any one marked "active" from the 4 primaries partition. WinXp is the least supportive among the modern boot loaders but can still do 10 systems.

Presto---there he is!!! You don't even have to search.

To a Windows user, "dual-boot" is a huge step. Many don't know what is a partition, what is boot code, etc.