HOW TO INSTALL 'previous systems'

Here is an Apple support topic on Previous System folder:

Here is a list of where your important data is stored
("~" stands for "Home"):

Your data in ~/Documents
~/Library/Application Support/AddressBook (copy the whole folder)
~/Library/Application Support/iCal(copy the whole folder)
Also in ~/Library/Application Support (copy whatever else you need)

~ /Library/Keychains (copy the whole folder)
~/Library/Mail (copy the whole folder)
~/Library/Preferences/com.apple.mail.plist This is a very important file which contains all email account settings and general mail preferences.

~ /Library/iTunes (copy the whole folder)
~/Library/Application Support/Safari (copy the whole folder)
~/Library/Application Support/iMovie (copy the whole folder)
~/Pictures/iPhoto library
~/Music/iTunes
~/Movies/iMovie

If you want cookies:
~/Library/Cookies/Cookies.plist
~/Library/Application Support/Webfoundation/HTTPcookies.plist

For Entourage users:
Entourage is in Documents/Microsoft user data
Also in ~ /Library/Preferences/Microsoft


-mj

 

Although that is very helpful information, the OP seems to be wanting to know how to undo the upgrade to leopard essentially.

Here is my suggestion, however, it only works if you have an external hard drive (or another hard drive period i guess)

Make sure said other drive is empty, and large enough to hold all your data.

Download and install CarbonCopyCloner, and run it, cloning your system drive to the empty partition/drive.

Restart your computer off that partition to make sure that everythign worked.

Restart your computer again, this time with the Tiger Restore Disks in the drive. Tell the machine to either A) Archive and Install or B) Erase and Install (if A is not an option).

If B happens, then after you install Tiger to the partition that Leopard was just on, you can then, during the final stages, have it migrate from another mac, and then you can point it to that clone that you made.