How can one install different operating systems On one computer?

first go to BIOS and change first boot device to cdrom and put bootable cd of OS after that select different partion drive for installing otherwise if u select the same drive for both partion it may chance to loss data .after you select the drive setup option will appear and go through necessary step to complete installation .after that computer will restart and you can see dual boot option u can select operating system and load.

Thanks

Rinil 

By Virtualization of Machines,

First put the CD of the second operating ssystem of your choice into the CD-ROM drive of your PC. Then, restart your PC and login to your bios setup to make CD-Rom drive first in the boot order. Save and exit.

Click on any button when prompted and copying of the setup files automatically begins.

WARNING!!! Do not select format drive at all, please this will lead to the loss of your data. Choose install into another folder, this will make the former operating system and the new operating system to be existing side by side.

The rest are just simple information you put and desired user name of your choice. When the installation is completed and you restart, you will see the two operating systems and you can always choose which one you want to login into. All the best

There is utilities to do this. But also you can do with installing like a VM(virtual machine).