can't install/copy mounted part.'s files - is it hardware trouble?

[mikrolux]

strange

i was an apple user before

but i never saw this thing

 

i mount any app (dmg file) or insert a dvd with app. or other files

and !!!! i can't copy any file in finder

i've tried Disk Utility and to change Ownership & Permissions - no result

 

 

my config is Dell Inspiron 1300

Jas 10.4.8

it's my 4th install i believe

this is my first time i have this problem