restoring my system manually

Well, Since i have no backup (that will be resolved shortly) I need to restore my system . My first issue is when clicking on the attachment to an e mail my desktop items automatically appear on my screen and i am unable to minimize the size because quite frankly i am not sure how to. I did see a few lines on the bottom of the screen that i could drag to size it to my liking but it is hidden.
Secondly in my desktop file there are 100 pictures that downloaded before i panicked and "quit safari" . What to do with them....

Help us to help you by posting which Mac you have, year and model. Also what version of OS X it's running. Thanks.

iMAC OS X 10.5.8

If you have the origional restore disks to the machine boot them on the imac holding c at the chime with the disk in. boot to the disk and then press utilities and open disk utility. Select the hard drive and then partition it so that you can do a fresh install of OS X leopard. Install it on the new partition and then boot to that after wards. when you are finished you can try and recover the files from the old system.